1987 HVAC VACUUM LEAK TESTING AND REPAIR PROCEDURE

 

Some of the HVAC controls on Virginia were not working correctly when we first got her so I did some testing, found the problem and made the repair during the time when I had the engine all tore apart. Since this was my first attempt to repair the HVAC vacuum system, I used John Pirtle's outstanding write-up on the subject and found it extremely valuable. THANKS, John!

This is another Newbie rated thread with lots of pictures for those like me that have not tried this before and would like a step-by-step pictorial guide. Even though there are 4 vacuum actuators of interest in the HVAC system, I only needed to repair 2 since the other 2 were still working famously. The two that will be discussed in this thread are the Footwell Flap actuator and the comb flap actuator.

First, if you suspect some problems with the HVAC vacuum system, you can verify it rather easily without taking anything apart (except one vacuum hose near the brake booster). You will need a vacuum pump (such as a MityVac). Locate the black HVAC vacuum source (input) line that is located just under the brake booster. Disconnect it from the 4-way splitter as shown - and back by popular demand, my hand model!
Name:  01.jpg
Views: 0
Size:  60.2 KB

Next, I use a small rubber vacuum hose extension (about 6") and attach the rubber hose to the HVAC source line.
Name:  01.1.jpg
Views: 0
Size:  51.1 KB

Then attach your vacuum pump to the rubber hose extension.
Name:  01.2.jpg
Views: 0
Size:  59.9 KB

I pump the vacuum up to about 17-18 Inches HG. If there are no leaks between the vacuum pump and the vacuum manifold inside the center console, it should hold vacuum.
Name:  01.3.jpg
Views: 0
Size:  71.8 KB

If you are leaking vacuum at this point, check the line from the vacuum pump into the firewall. If no leaks yet, insert the key in the ignition and turn the key to the "run" position (or you can simply start the car). This will power the electric solenoids that divert vacuum to the vacuum actuators in the HVAC system. You will notice a drop in the vacuum on the vacuum pump as vacuum is routed to the actuators in the HVAC system. Begin pumping the vacuum back up (about 12-15 pumps) until you get back to about 15 Inches HG. See if it will hold vacuum at this point. If it holds vacuum, you can try moving the HVAC control slider knob on the head unit and see if it holds vacuum in all positions. If you see vacuum steadily dropping, you have a leak.

Once you have confirmed you have a leak, you can gather your tools and parts. Here's the commonly used tools I used for the procedure:

Phillips screwdriver (including a stubby or 90 degree Phillips)
10mm socket, extension, ratchet
3/4" drill bit, drill
3/4" plastic or rubber body plug
MityVac Vacuum pump
Replacement Vacuum Diaphragms (I ordered all 4 diaphragms from Roger before digging in because I wanted to have all the parts I would need in case they were all bad). Roger had 3 of the 4 vacuum diaphragms and the defroster vacuum actuator itself - so I was all set.

You will need to remove the center console side panels in order to get at the HVAC vacuum manifold to conduct further testing and pinpoint the leak. First, remove the under dash shelves/trays on the driver's side and passenger side. Use a 10mm socket on the two acorn nuts under the dash as shown.
Name:  02.jpg
Views: 0
Size:  84.7 KB

Next, remove the 10mm nut on the right end of the tray.
Name:  03.jpg
Views: 0
Size:  125.0 KB

Then the 10mm nut on the left side of the tray. It's easier to use an extension for this nut.
Name:  04.jpg
Views: 0
Size:  91.1 KB

Once the nut is off the left side, pop the carriage bolt up and out. This will make it easier to remove the tray. Bag and mark the hardware so it doesn't get lost.
Name:  05.jpg
Views: 0
Size:  116.2 KB

Now you can maneuver the tray out.
Name:  06.jpg
Views: 0
Size:  92.4 KB

Next, remove the foot guard. It's held in place by three phillips screws. Take all three out....
Name:  07.jpg
Views: 0
Size:  137.2 KB

...and remove the plastic guard. Note that at the far end of the guard, there is a notched tab that fits behind the accelerator and locks the guard in place (unfortunately not pictured here - it's blocked by the accelerator here).
Name:  08.jpg
Views: 0
Size:  132.2 KB

Next, remove the side panel by removing the two phillips screws - one is located near the front as shown.
Name:  09.jpg
Views: 0
Size:  125.3 KB

Remove the rear Phillips screw located as shown.
Name:  10.jpg
Views: 0
Size:  104.5 KB

Then pull the side panel down removing it from its groove in the console.
Name:  11.jpg
Views: 0
Size:  129.2 KB

Pull the front end of the panel out toward the car door to remove it from the metal tray bracket and pull out the panel.
Name:  12.jpg
Views: 0
Size:  98.2 KB

After removing the console side panel, you will notice the hard plastic vacuum hoses in multiple colors that feed the various vacuum actuators of the HVAC system. These will be described in a moment.
Name:  13.jpg
Views: 0
Size:  121.7 KB

You have a couple of options here to conduct the next test. You will notice you can't access all of the vacuum hose connections at the solenoid. In fact, I could only access the last one (yellow, pictured below) to pull the vacuum line and test with the MightyVac. You can cut each of the hard lines and attach the MightyVac to the end of the hose that runs up into the dash. If everything checks out, you can simply re-connect the severed connection with a rubber vacuum hose coupling. The other option you have is to remove the vacuum solenoid console (which is what I did) so you can access all the vacuum line connections at the solenoids and test the lines without cutting. I discovered here that my yellow line (goes to the foot well flap vacuum actuator) had a leak so I was going to have to remove the center console anyway to repair it. I might as well remove the solenoid console to test the rest of the actuators for leaks.
Name:  14.jpg
Views: 0
Size:  90.1 KB

Next, remove the brace that holds the under dash tray. It's held on by a 10mm nut.
Name:  15.jpg
Views: 0
Size:  125.6 KB

Going over to the passenger side, remove the under dash tray and center console cover as you did on the driver's side. One difference you will notice is the passenger side under dash tray has a lamp monitor attached to the outer end of the tray (near the car door). You can either disconnect the electrical harness or remove the monitor box from the tray with the two mounting bolts in order to remove the tray.
Name:  16.jpg
Views: 0
Size:  87.2 KB

Remove the center console side cover.
Name:  17.jpg
Views: 0
Size:  120.9 KB

You will find a Phillips screw that holds the solenoid console protective cover in place (see pic). Remove the Phillips screw.
Name:  18.jpg
Views: 0
Size:  121.6 KB

You will find the same screw on the driver's side. Remove it as well.
Name:  19.jpg
Views: 0
Size:  120.0 KB

Once the screws are removed, the cover will drop down. The solenoid console is held in place by one final Phillips screw in the center of the mounting bracket (see arrow in pic). There isn't much room to remove this screw.....
Name:  20.jpg
Views: 0
Size:  119.8 KB

....In order to gain a little more working room, I pulled out the vacuum solenoid console cover as shown.....
Name:  21.jpg
Views: 0
Size:  123.2 KB

....and pulled out the radio a few inches. In order to pull out the radio, you will need the installation "keys" to pull the radio (your radio will differ). Since I was going to have to remove the radio as part of the console removal process anyway, this seemed like a reasonable thing to do.
Name:  22.jpg
Views: 0
Size:  94.9 KB

With a little more room to work with, I used a 90 degree Phillips screwdriver to get the screw out. A stubby Phillips screwdriver works well here too.
Name:  23.jpg
Views: 0
Size:  112.4 KB

With the center screw removed, you can pull out the solenoid console out the driver's side as shown. There is one vacuum source line (black) and 5 output lines - one from each solenoid. They are marked in the pic below as to what function each color line performs and the location of the vacuum actuator. Yellow goes to the foot well flap, green goes to the defrost flap, orange goes to the comb flap, white goes to the hot water control valve, and blue goes to the recirculation flap.
Name:  24.jpg
Views: 0
Size:  123.7 KB

You can test each line one at a time by disconnecting the line from the solenoid and attaching the Mightyvac to the rubber hose connection. I applied about 15 inches HG and listened for the flap movement and watched the vacuum gauge to see if it would hold vacuum. If everything checked out, I reconnected the line and move to the next. I found that I had a leak in the Yellow (footwell flap) and the orange (comb flap) lines. The rest of the lines all held vacuum and operated the flaps. For me, the next steps would be to remove the center console to get at the to leaking actuators. If you find that you have a leaking defroster actuator, you will need to remove the instrumentation pod to get to it. If the hot water control valve is leaking vacuum, you will need to remove the air filter box in the engine bay in order to get at the actuator. If you have a leak in the recirculation flap, you will need to remove the fan blower motor and recirculation box above the CEB to get at the actuator.
Name:  25.jpg
Views: 0
Size:  112.7 KB

If you have tested all the vacuum lines to their respective actuators and did not find a leak, then the leak is most likely in one of the vacuum solenoids. There are 5 solenoids and any one or all may be leaking vacuum. Even if you found a leak at one of the actuators, it's a good idea to test the solenoids as well - and now is the perfect time. The quick and easy way to test all the solenoids at once is to hook up the mighty vac to the rubber vacuum manifold where the source vacuum line (black line) comes in. Disconnect all the vacuum lines that go to the actuators and cap the vacuum port at the solenoid with a vacuum cap as shown below. Pump up the vacuum to about 15 inches Hg and turn the ignition switch to "run". If the vacuum does not hold, then you have a leak in one or more of the solenoids. When I checked
Virginia (87) during this procedure, all solenoids were good and vacuum tight. However, when I performed this test on California ('84), 4 out of the 5 solenoids leaked vacuum. So I ordered 4 used ones from 928 Intl and now they are all working. To pinpoint the leaking solenoid, remove the rubber vacuum manifold and plug the Mightyvac directly into each input port of each solenoid (one at a time) and pump up the vacuum, turn on the ignition to "run" and see if it will hold vacuum. Operate the bottom slider knob on the A/C control unit to energize the different solenoids. I found my old solenoids would hold vacuum when the ignition was off but would leak when power was applied. If you find a leaking solenoid, they are easy to replace: remove the electrical wire and remove the Phillips screw on the bottom of the solenoid mounting plate and the solenoid is free to be replaced.
Name:  200.jpg
Views: 0
Size:  74.8 KB

Before proceeding with removing the center console, I recommend you disconnect the negative terminal to the battery since you will be disconnecting several wiring harnesses.

To remove the center console: Finish removing the radio by disconnecting the wiring harness, antenna and ground wires from the rear of the radio and remove the radio unit.

Next, remove the center vent deflector vanes. I found a 90 degree pick tool to work well here. Just catch the inside of the vane unit as shown and pull outward on one side followed by the other side.
Name:  27.jpg
Views: 0
Size:  119.5 KB

With both sides free, you can remove the center vent deflector vanes.
Name:  28.jpg
Views: 0
Size:  105.8 KB

Next, remove the A/C control unit/radio trim piece. I used the same 90 degree pick tool. I pushed up slightly (toward the center vent) and pulled out using the pick tool at the same time.
Name:  29.jpg
Views: 0
Size:  122.1 KB

It's a tight fit but with a little care and patience, it will come out undamaged.
Name:  30.jpg
Views: 0
Size:  117.3 KB

The A/C control unit is held in place with four Phillips screws (2 on each side). The A/C switch and warning strip is held in place with two Phillips screws (1 on each side). Remove all 6 of these screws.
Name:  31.jpg
Views: 0
Size:  123.5 KB

Next, disconnect the wiring harness plug from the back of the A/C switch.
Name:  32.jpg
Views: 0
Size:  109.9 KB

Then disconnect the 6-wire and 4-wire wiring harness connectors that are attached to the warning strip.....
Name:  33.jpg
Views: 0
Size:  84.6 KB

....and remove the warning strip.
Name:  34.jpg
Views: 0
Size:  113.2 KB

Next, pull out the A/C control unit. You will notice two wiring harness connections (see arrows).
Name:  35.jpg
Views: 0
Size:  109.9 KB

You can pry off the front harness connection.....
Name:  36.jpg
Views: 0
Size:  132.5 KB

....and pull off the rear harness connection.
Name:  37.jpg
Views: 0
Size:  108.3 KB

Then, remove the A/C control unit.
Name:  38.jpg
Views: 0
Size:  95.6 KB

My control unit had broken slider knobs as shown here. I will be repairing these later in this post.
Name:  39.jpg
Views: 0
Size:  107.4 KB

Next, disconnect the wires at the back of the clock. Note the color of the wires and the terminal the wire is connected to for re-installation.
Name:  40.jpg
Views: 0
Size:  68.8 KB

Then, disconnect the wires at the back of the cigarette lighter. Note the color of the wires and the terminal they are connected to. There is a black wire with yellow stripe and a black wire with a blue stripe and a pair of ground wires.
Name:  41.jpg
Views: 0
Size:  97.9 KB

Next, remove the two 8-mm bolts at the top of the center vent. One on the driver's side here as shown.
Name:  42.jpg
Views: 0
Size:  94.2 KB

I used a combination wrench to get at the 8mm bolt on the passenger side.
Name:  43.jpg
Views: 0
Size:  120.1 KB

Next, remove the two Phillips screws under the dash on the driver's side that hold the center console to the dash.
Name:  44.jpg
Views: 0
Size:  118.2 KB

Remove the cover plug inside the glove box as shown.
Name:  45.jpg
Views: 0
Size:  76.2 KB

Loosen the 8mm hex head screw with a socket and extension as shown.
Name:  46.jpg
Views: 0
Size:  92.5 KB

When the screw is loosened, you can use a magnetic pick up tool to pull the screw out.
Name:  47.jpg
Views: 0
Size:  91.6 KB

Remove the two Phillips screws under the dash on the passenger side as shown.
Name:  48.jpg
Views: 0
Size:  101.4 KB

Disconnect the rear wiper switch harness.
Name:  49.jpg
Views: 0
Size:  90.8 KB

Disconnect the passenger side window switch wiring harness. This '87 did not have a sunroof so no sunroof harness to disconnect. If you have a sunroof, you will need to disconnect that harness connector as well.
Name:  50.jpg
Views: 0
Size:  129.5 KB

Clip the harness tie down.
Name:  51.jpg
Views: 0
Size:  110.5 KB

And remove the harness from the tape as shown.
Name:  52.jpg
Views: 0
Size:  109.2 KB

Pull out the wiring harnesses so they are free of any entanglements,
Name:  53.jpg
Views: 0
Size:  145.0 KB

Next, disconnect the driver's side window switch wiring harness.
Name:  54.jpg
Views: 0
Size:  131.7 KB

Remove the harness from the tape as shown.
Name:  55.jpg
Views: 0
Size:  133.7 KB

Remove the two Phillips screws that secure the rear of the center console. There's one screw on each driver's/passenger's side.
Name:  56.jpg
Views: 0
Size:  119.6 KB

For automatics, you will need to lower the shift handle all the way down to "2". For Manuals, you will need to place the shifter in neutral.
Name:  57.jpg
Views: 0
Size:  84.3 KB

Next, remove the shift handle. Pull down the shifter boot to expose the handle mounting screws and remove. There's one on each side of the handle. Unfortunately, mine had one flat blade screw and one Phillips screw so I'm not sure which was original. For manual, you will need to remove the top of the shift stick.
Name:  58.jpg
Views: 0
Size:  78.1 KB

Remove the handle by lifting straight up.
Name:  59.jpg
Views: 0
Size:  81.4 KB

Remove the boot by pulling the base way from the groove in the shift plate and lifting up over the shift lever.
Name:  60.jpg
Views: 0
Size:  96.1 KB

Disconnect the shift plate from the shift lever by slightly prying the notched tabs out away from the shift lever as shown.
Name:  61.jpg
Views: 0
Size:  104.0 KB

Next, pull back on the center console a few inches.
Name:  62.jpg
Views: 0
Size:  103.8 KB

Lift up at the rear of the console.....
Name:  63.jpg
Views: 0
Size:  138.6 KB

....while pulling back toward the rear of the car.
Name:  64.jpg
Views: 0
Size:  107.6 KB

There are two more wiring harness connectors to disconnect. These go to the shift plate. Disconnect these wires (a 2-wire plug and a 4-wire plug). Then remove the console.
Name:  65.jpg
Views: 0
Size:  116.4 KB

The foot well flap vacuum actuator and comb flap vacuum actuator will now be exposed as shown by the arrows. Inspect the vacuum hose connections for leaks. If it's solidly connected, and the hose is not damaged, the vacuum diaphragm inside the housing is in need of repair.
Name:  66.jpg
Views: 0
Size:  111.2 KB

Start with the foot well actuator by disconnecting the yellow vacuum line.
Name:  67.jpg
Views: 0
Size:  98.0 KB

You can repair the diaphragm with the actuator housing in place. We need to remove the cap and disconnect the lever arm in order to remove the diaphragm. To remove the top, depress the locking tabs on the top (4 of them). I used a pair of needle nose pliers as shown.
Name:  68.jpg
Views: 0
Size:  110.9 KB

When the tabs are released, the top will come off - be careful to hold the top in place as you release the tabs because the top is under spring load. Remove the top.
Name:  69.jpg
Views: 0
Size:  80.7 KB

Remove the spring noting the orientation, small end on the diphram and large end against the top as shown.
Name:  70.jpg
Views: 0
Size:  100.4 KB

Next, use a small screwdriver to pry the plastic lock pin out just enough to release the metal actuator lever arm.
Name:  71.jpg
Views: 0
Size:  92.6 KB

With the lever arm free, bend the arm just enough to allow you to maneuver the diaphragm and lever arm out of the plastic housing. Don't worry, you will be able to easily bend it back to it's original shape.
Name:  72.jpg
Views: 0
Size:  114.1 KB

Now you can simply lift out the vacuum diaphragm as shown.
Name:  73.jpg
Views: 0
Size:  108.6 KB

Here's the diaphragm and lever arm removed and the new diaphragm from Roger.
Name:  74.jpg
Views: 0
Size:  137.6 KB

You remove the old diaphragm by pulling it back over the lever arm as shown. Notice the small split in the diaphragm that was causing the leak.
Name:  75.jpg
Views: 0
Size:  128.7 KB

Continue pulling off the diaphragm until completely removed.
Name:  76.jpg
Views: 0
Size:  126.9 KB

Insert the new diaphragm onto the lever arm oriented the same direction as the old diaphragm (as shown).
Name:  77.jpg
Views: 0
Size:  130.6 KB

When the new diaphragm is fully seated on the lever arm, it should look like this.
Name:  78.jpg
Views: 0
Size:  133.6 KB

Next, place the end of the lever arm back through the bottom of the vacuum container as shown.
Name:  79.jpg
Views: 0
Size:  103.7 KB

Using pliers, bend the end of the lever arm back to it's original configuration.....
Name:  80.jpg
Views: 0
Size:  109.6 KB

....it should look something like this.
Name:  81.jpg
Views: 0
Size:  97.0 KB

Next, reattach the lock pin at the end of the lever arm.
Name:  82.jpg
Views: 0
Size:  103.0 KB

Install the spring with wide opening facing up.
Name:  83.jpg
Views: 0
Size:  103.4 KB

Install the cap oriented in the same manner as it came off.
Name:  84.jpg
Views: 0
Size:  77.6 KB

Ensure the diaphragm is sealed properly all around on the top and bottom rims of the vacuum container (i.e., not pinched or distorted)
Name:  85.jpg
Views: 0
Size:  92.7 KB

Snap the top of the vacuum container into place ensuring all four tabs lock.
Name:  86.jpg
Views: 0
Size:  90.4 KB

Re-attach the vacuum hose.
Name:  87.jpg
Views: 0
Size:  88.5 KB

Next, test the new diaphragm for operation and leaks. Disconnect the yellow vacuum line from the solenoid console (if not already disconnected) and attach the Mightyvac. Not the at rest position of the lever arm.
Name:  88.jpg
Views: 0
Size:  102.5 KB

Pump up the vacuum and watch for movement of the lever arm.
Name:  89.jpg
Views: 0
Size:  99.6 KB

Note the vacuum required to "bottom out" the lever arm and wait to see if the vacuum holds. In this case everything is working fine.
Name:  90.jpg
Views: 0
Size:  96.5 KB

Next, I needed to work on the Comb flap diaphragm. In order to "re-connect" the lever arm on this actuator, it was easier to remove the glove box to gain access to the lever arm connection. I went ahead and removed the glove box now. Start by removing the two Phillips screws that hold the upper portion of the box to the dash (one on the left and one on the right).
Name:  91.jpg
Views: 0
Size:  88.0 KB

Then remove the 3 Phillips screws underneath the glove box door at the hinge as shown.
Name:  92.jpg
Views: 0
Size:  117.1 KB

Next, remove the latch by removing the two Phillips screws that attach the latch to the top of the glove box as shown.
Name:  93.jpg
Views: 0
Size:  86.4 KB

Then locate the glove box light harness connection. It's located above and behind the EZK and LH computers. The wires should be held in place by a wire strap as shown.
Name:  94.jpg
Views: 0
Size:  117.2 KB

Disconnect the wire harness and remove the wire from the hold down strap.
Name:  95.jpg
Views: 0
Size:  98.0 KB

Pull the glove box out enough to see the vent hose connection and disconnect the vent hose from the glove box.
Name:  96.jpg
Views: 0
Size:  77.8 KB

Now, you can remove the glove box.
Name:  97.jpg
Views: 0
Size:  122.9 KB

Next, disconnect the HVAC hose from the air distribution box as shown. This will give you access to the comb flap actuator arm connection inside the air distribution box. You can view the connection using a flashlight or snake light. Access from this angle was particularly handy for re-connecting the lever arm to the flap when I was re-installing the new diaphragm.
Name:  98.jpg
Views: 0
Size:  110.3 KB

Back to removing the old diaphragm. Press back the plastic tabs on the vacuum container lid as you did on the foot well vacuum container remembering the lid is spring loaded.
Name:  99.jpg
Views: 0
Size:  107.1 KB

Remove the lid and the spring.
Name:  100.jpg
Views: 0
Size:  91.1 KB

At this point, there are a couple of methods for disconnecting the vacuum lever arm at the flap lever arm (the connection is inside the air distribution box). The connection is similar to the lock pin connection you just dealt with on the foot well vacuum lever arm above. I believe the easiest method is to simply rotate the diaphragm/lever arm and the arm will "pop" off the lock pin at the connection to the comb flap. Then extract the vacuum lever arm as described in a few pictures from here (THANKS to "Aryan" and "Xlot" for this tip!). The other method, the one I followed and documented here, is to drill a hole in the distribution box big enough to insert a screwdriver to "pop" the lock pin connection. This method is more work and will require a body plug to be installed to plug the hole in the air distribution box. I drilled a 3/4" hole in the air distribution box right between the vent and the comb flap vacuum container.
Name:  101.jpg
Views: 0
Size:  92.1 KB

After the hole is drilled, you will be able to view the connection of the vacuum lever arm to the comb flap.
Name:  102.jpg
Views: 0
Size:  114.9 KB

Using this method, I found it very easy to disconnect the vacuum lever arm from the comb flap by using a flat blade screwdriver. Insert the screwdriver between the lock pin and lever arm and twist and it will pop right off.
Name:  103.jpg
Views: 0
Size:  108.1 KB

You can then pull out the diaphragm and lever arm as shown.
Name:  104.jpg
Views: 0
Size:  90.8 KB

Replace the diaphragm as described earlier on the foot well diaphragm.
Name:  105.jpg
Views: 0
Size:  101.4 KB

Re-insert the lever arm back into the air distribution box as shown.
Name:  106.jpg
Views: 0
Size:  95.4 KB

Re-connect the diaphragm lever arm to the comb flap by entering the air box from the port behind the glove box. Line up the pin and press on the connection with the screwdriver until the lock pin clicks into place. If needed, you can counterhold the lever arm through the front 3/4" hole we cut earlier using another screwdriver.
Name:  107.jpg
Views: 0
Size:  73.1 KB

Position the spring with larger opening facing out.
Name:  108.jpg
Views: 0
Size:  88.9 KB

Position the lid ensuring the diaphram is properly seated on the lid and bottom rims of the vacuum container.
Name:  109.jpg
Views: 0
Size:  84.4 KB

Snap the lid into place ensuring all four tabs lock into place and re-connect the vacuum hose to the vacuum lid.
Name:  110.jpg
Views: 0
Size:  92.0 KB

Connect the Mightyvac to the other end of the orange vacuum line (at the solenoid console) and note the position of the comb flap at rest.
Name:  111.jpg
Views: 0
Size:  101.5 KB

Pump up the vacuum and watch the comb flap move up - it should move freely.
Name:  112.jpg
Views: 0
Size:  102.8 KB

Note when the comb flap reaches maximum and the note the vacuum level. Then watch the gauge to confirm it holds vacuum. Everything checked out OK here!
Name:  113.jpg
Views: 0
Size:  114.2 KB

Now you're done with the foot well and comb flap diaphragm repair and you can begin reassembling the center console. First, reconnect any disconnected vacuum lines at the solenoid console and ensure all hoses are fully seated.
Name:  114.jpg
Views: 0
Size:  89.3 KB

Next, slide the vacuum solenoid console back into position in the center console.
Name:  115.jpg
Views: 0
Size:  90.0 KB

Slide the vacuum solenoid console plastic protective cover into place.
Name:  116.jpg
Views: 0
Size:  114.2 KB

It is a personal preference to re-install the center mounting screw on the vacuum console. I left it off since I felt the two outer screws were sufficient to hold the vacuum console in place. If you want to the put the "hard to get to" center screw back in, now's the time to do it. Then attach the two end screws with the plastic cover as shown.
Name:  117.jpg
Views: 0
Size:  121.7 KB

Next, I needed to repair the slider knobs on the A/C control unit. I began by removing the old slider knobs.
Name:  120.jpg
Views: 0
Size:  145.7 KB

Here's what the new slider knobs look like along side the knob's sliding spring. The new springs are a different shape than the originals but work just fine. When installing the new slider knobs, ensure they are positioned correctly. The top knob should be oriented so the pointer on the face of the knob is pointing downward (as shown) while the bottom slider knob pointer is facing up.
Name:  121.jpg
Views: 0
Size:  145.6 KB

Next, carefully pry and dislodge the top and bottom locking tabs using a small screwdriver so the face place can be removed. However, also.....
Name:  122.jpg
Views: 0
Size:  133.6 KB

....dislodge the lock tabs on the ends of the face plate as well before removing the face plate.
Name:  123.jpg
Views: 0
Size:  77.8 KB

With the face place moved out of the way, you can remove the old slider spring. Note the optical fiber lighting cable in the center of the spring. This cable provides light for the slider knob.
Name:  124.jpg
Views: 0
Size:  129.8 KB

Install the new slider spring in the same manner as the old spring with the optical fiber going through the center of the slider spring as shown. Perform the same procedure for the other slider knob if it's being repaired as well.
Name:  125.jpg
Views: 0
Size:  138.8 KB

Install the face plate and press it into position ensuring all the lock tabs are properly seated. Then, position the slider knob so the optical fiber cable is inserted into the center hole of the slider knob. You should see plenty of cable showing on the top of the slider knob as shown here. Line up the slider knob prongs with the slider spring and receiving clip on the control unit and press the slider knob into place until it clicks into place. Perform the same operation for both slider knobs. I used silicone lubricant to lube the slider spring and track (you could also use white general purpose grease). Test the operation of the slider knobs by moving the sliders to maximum ends of travel. Also note there are detents and button switches at the end of travel on the temperature rail - the slider should easily slide into these detents at the end of travel. If not, you may have an obstruction or the slider knob may not be fully seated.
Name:  126.jpg
Views: 0
Size:  105.5 KB

Next, I re-attached the hose at the air distribution box (behind the glove box).
Name:  119.jpg
Views: 0
Size:  88.6 KB

Then I positioned the heat shield fabric (for the cigarette lighter) back into its original location and cut a strip of duct tape to hold it down. Cut the duct tape with plenty of length as it will also hold down the wiring harness for window switches and rear wiper switch.
Name:  127.jpg
Views: 0
Size:  103.1 KB

To plug the 3/4" hole I made for the comb flap, I purchased an assortment of body plugs (plastic in this case). Here's the 3/4" size I used to plug the hole.
Name:  128.jpg
Views: 0
Size:  131.2 KB

Install the plug in the 3/4" hole.
Name:  129.jpg
Views: 0
Size:  120.3 KB

Now you can position the center console. Start by lifting the rear of the console up while positioning the front at the dash.
Name:  130.jpg
Views: 0
Size:  132.1 KB

Then line up the rear of the console with the shift lever and lower the console over the lever as shown.
Name:  131.jpg
Views: 0
Size:  136.4 KB

With the console laying in place, reconnect up the clock wires to the same terminals as they were removed (see below).
Name:  132.jpg
Views: 0
Size:  69.1 KB

Likewise, attach the wires for the cigarette lighter as shown.
Name:  133.jpg
Views: 0
Size:  89.0 KB

Next, connect the passenger window switch wiring lead to the wiring harness.
Name:  134.jpg
Views: 0
Size:  133.2 KB

Connect the rear wiper switch wiring lead to the wiring harness. If you have a sunroof, connect it's wiring lead to the harness at this time.
Name:  135.jpg
Views: 0
Size:  85.0 KB

On the driver's side, route the driver's window switch wiring lead behind the central locking module.
Name:  136.jpg
Views: 0
Size:  116.5 KB

Then connect the window switch wiring lead to the wiring harness as shown.
Name:  137.jpg
Views: 0
Size:  142.0 KB

Next, connect the A/C switch harness plug to the back of the A/C switch on the central warning strip as shown.
Name:  138.jpg
Views: 0
Size:  109.3 KB

Underneath the console, connect the 6-wire and 4-wire leads from the central warning strip to their matching wiring harness plugs as shown.
Name:  139.jpg
Views: 0
Size:  109.1 KB

Locate the 4-wire and 2-wire leads from the shifter plate. Connect the 4-wire lead to its corresponding wiring harness plug as shown.
Name:  140.jpg
Views: 0
Size:  86.2 KB

and connect the 2-wire lead to the wiring harness plug.
Name:  141.jpg
Views: 0
Size:  83.9 KB

Next, position the A/C control unit near the center console opening and connect the rear wiring harness as shown.
Name:  142.jpg
Views: 0
Size:  111.1 KB

Then connect the front wiring harness.
Name:  143.jpg
Views: 0
Size:  99.2 KB

Install the A/C control unit and central warning strip in their assigned positions in the center console.
Name:  144.jpg
Views: 0
Size:  114.2 KB

Secure the A/C control unit and central warning strip with their corresponding Phillips screws (2 each side for the A/C control unit and 1 each side for the warning strip).
Name:  145.jpg
Views: 0
Size:  101.9 KB

Next, install the console plastic trim piece. Position the trip piece on one side first....
Name:  146.jpg
Views: 0
Size:  116.1 KB

...and press into place. Then press the other side into place. It's a snug fit to get the other side in. To help get the other side in, I very carefully applied pressure to the horizontal piece of the trip (pulling up on the center piece) to allow it to slip into place a little easier.
Name:  147.jpg
Views: 0
Size:  107.7 KB

Position the window switch and rear wiper switch wiring harnesses on the passenger side under the duct tape that was attached to the heat shield cloth installed earlier. Do the same for the driver's side with the driver's side window switch wiring harness.
Name:  148.jpg
Views: 0
Size:  96.5 KB

Slip the end of the duct tape under the carpet and press firmly into place.
Name:  149.jpg
Views: 0
Size:  105.1 KB

Position the stereo unit near its assigned position in the console and re-connect the wiring connections at the rear of the unit (power, speakers, ground, and antenna).
Name:  150.jpg
Views: 0
Size:  119.3 KB

Carefully slide the stereo unit into its slot, guiding it from the rear while maneuvering the wiring behind the unit out of the way. My unit had a "C" shaped receiver secured to the floor so I guided the stereo unit into the "C".
Name:  151.jpg
Views: 0
Size:  130.2 KB

Press the stereo unit into place from the front until it is fully seated.
Name:  152.jpg
Views: 0
Size:  125.5 KB

Install the two Phillips screws that secure the bottom of the console to the dash. The passenger side is pictured here. Do the same for the two Phillips screws on the driver's side.
Name:  153.jpg
Views: 0
Size:  107.6 KB

Install the under dash tray bracket (driver's side) using the 10mm nut and tighten down.
Name:  154.jpg
Views: 0
Size:  132.8 KB

Install the two 8mm bolts above the center vent that secure the console to the dash.
Name:  155.jpg
Views: 0
Size:  116.7 KB

Install the 10mm screw at the glove box
Name:  156.jpg
Views: 0
Size:  81.6 KB

Next, attach the sliding shifter plate to the shift lever by spreading the notched tabs slightly apart and insert the notches on both sides into their corresponding slots in the shift lever.
Name:  157.jpg
Views: 0
Size:  86.1 KB

Install the shift boot and secure the bottom of the boot to the shift plate base. The boot should fit flush against the shift plate.
Name:  158.jpg
Views: 0
Size:  79.3 KB

I decided to lubricate the shift locking release mechanism. It is easily removed by simply lifting up as shown.
Name:  159.jpg
Views: 0
Size:  89.9 KB

I lubricated the mechanism using general purpose white grease.
Name:  160.jpg
Views: 0
Size:  126.4 KB

Then placed the shift locking mechanism back into the shift lever in the same orientation as it was originally.
Name:  161.jpg
Views: 0
Size:  67.1 KB

Next, install the shift handle lining up the two Phillips screw holes. I tested the shift locking button to make sure it was lined up and working properly before tightening the handle mounting screws. If the locking mechanism isn't working properly, remove the handle, check for obstructions and try re-aligning the handle with the locking mechanism again. When it's working properly, tighten down both screws and raise the shift boot to cover the exposed screw heads.
Name:  162.jpg
Views: 0
Size:  115.9 KB

When I removed the rear mounting screws on the center console, the passenger side was broken in half as pictured below. I ordered the repair kit from Nicole.
Name:  163.jpg
Views: 0
Size:  123.2 KB

Nicole sells a nice center console rear mounting tab repair kit which includes the metal reinforcement plates and mounting screws. THANKS Nicole!
Name:  164.jpg
Views: 0
Size:  118.2 KB

The repair kit can be used to repair a broken tab such as mine as long as enough of the original tab remains to secure the reinforcing screws. The kit can also be installed over an undamaged console mounting tab (such as my driver's side) to prevent the tab from breaking in the future. I installed both reinforcing plates on both tabs. I also ordered a second kit to have handy for the next center console I have to take off because I want to reinforce all my center console tabs with this kit. To install the repair kit, simply follow the directions included with the kit. Here's the steps I followed. First get a drill and 3/32" drill bit. Position the reinforcing plate over the rear mounting tab ensuring the center hole in the metal plate lines up with the hole in the plastic center console mounting tab.
Name:  165.jpg
Views: 0
Size:  84.1 KB

Then, drill a pilot hole in each of the 2 mounting holes on the reinforcing plate as shown.
Name:  166.jpg
Views: 0
Size:  89.0 KB

Install the two Phillips screws that mount the reinforcing plate. Perform the same operation on the driver's side.
Name:  167.jpg
Views: 0
Size:  85.6 KB

Begin to install the rear mounting tab screw as shown.
Name:  168.jpg
Views: 0
Size:  83.7 KB

Ensure the center console is positioned correctly (evenly) at the rear and tighten the mounting tab screw down. Perform the same operation on the driver's side.
Name:  169.jpg
Views: 0
Size:  128.9 KB

Next, position the console side cover by lining up the slot in the side cover with the under dash tray mounting bracket and sliding it over the under dash mounting bracket. Then, push the side panel up into the side panel groove located along the outer edge of the center console.
Name:  170.jpg
Views: 0
Size:  120.2 KB

When you get to the rear of the console/side cover, you may notice the clearance between the side panel and the console is much reduced because of the mounting plate screws. The panel still fit but I had to carefully tuck the carpet up into the groove as I was pressing the side panel into the groove in the center console.
Name:  171.jpg
Views: 0
Size:  96.8 KB

Then tighten the rear side panel mounting screw and the front side panel mounting screw (Phillips). Repeat the side panel mounting sequence on the driver's side.
Name:  172.jpg
Views: 0
Size:  129.8 KB

Position the center vent cover and press into place until it is fully seated and flush against the center console. Note that it has 4 notch pins that must line up with holes in the console for installation.
Name:  173.jpg
Views: 0
Size:  93.9 KB

Next, position the glove box at the dashboard opening.
Name:  174.jpg
Views: 0
Size:  81.3 KB

Route the glove box light wiring harness over the top of the dash lower rail as shown.
Name:  175.jpg
Views: 0
Size:  75.8 KB

Attach the glove box vent hose to the port on the glove box.
Name:  176.jpg
Views: 0
Size:  113.7 KB

Insert the glove box/door unit into the dash opening and install the two phillips screws that attach the top of the glove box to the dash, as shown.
Name:  177.jpg
Views: 0
Size:  97.3 KB

Install the two screws that hold the glove box door catch but don't tighten down all the way. It will need to be adjusted later when checking operation of the glove box door.
Name:  178.jpg
Views: 0
Size:  129.1 KB

Next, ensure the glove box door hinges line up with the corresponding slot in the glove box....
Name:  179.jpg
Views: 0
Size:  142.7 KB

....and tighten the three Phillips screws at the bottom of the glove box door.
Name:  92.jpg
Views: 0
Size:  117.1 KB

Finally, take the end of the glove box light wiring lead....
Name:  180.jpg
Views: 0
Size:  90.2 KB

....and attach it to the wiring harness up behind the EZK and LH computers. Place the harness in the wire strap and secure as it was originally.
Name:  95.jpg
Views: 0
Size:  98.0 KB

If you determined that you had a leaking defroster flap actuator, you will need to remove the instrumentation pod to get to it. Here is a step-by-step procedure to removing the pod (http://forums.rennlist.com/rennforum...cs-part-i.html). Since you do not need to disassemble the pod in order to get at the actuator, you can skip the part about removing the control knobs and instrument cluster in the aforementioned post. Simple pull the pod toward the rear of the car and rotate face down over the steering column to give you space to work. Once the pod is pulled over the steering column, you can easily access the defroster actuator.

At this point, you can re-install the under dash trays for both driver and passenger sides if desired. On my daily driver, I left them off because it gives me extra leg room. On my wife's daily driver, I re-installed them since she doesn't need the extra room. The installation is the reverse of what was documented at the beginning of this post.

Congratulations! Now you can start the car and try out your newly repaired HVAC air distribution/temperature control system. Please feel free to comment or provide improvement suggestions on this post - I'm always looking for ways to improve the quality of these posts. THANKS for reading!