Touch Climat Control

rb68rr

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May 25, 2001
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Problem: Air blowing out defroster and floor but not vents. I've read about a hundred posts on this and still don't understand. What controls where the air is directed (vents, defroster, floor) on an 86' T-Type with the electronic touch control? The air will blow out of the defroster and the floor no matter which setting it's on. Thanks, R.B.
 

salvageV6

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There is an A/C defroster door (partially open by design) that is operated by the defroster door vacuum motor.

Vacuum controlled by the vacuum solenoid programmer triggered by the A/C control head.

The factory service manual would be your best bet trying to solve this problem.

The defroster door vacuum motor is located behind the I/P on the LH side of the A/C plenum follow the blue vacuum hose it operates it.

Operation is as follows: The A/c defrost door is in position B for all the cooling functions. In these modes the A/C defrost door vacuum valve is energized and vacuum is applied to its vacuum motor. When the DEF pushbutton is depressed the valve is DE-energized. It vents vacuum to the atmosphere and the door moves to position A. This directs the air flow to the Defrost outlets and the windshield.

There is also a heater-A/c door which has 3 postitions.

Sounds like you have a vacuum hose or two off or no vacuum to the system.

Worst case when working backwards from the valves it could be electronically with the control head or solenoids but I am a firm believer that electronics fail much less than the mechanical aspects of most systems.

You have to decide what direction to approach the problem from, I'd start with what vacuum is on what hoses at this time, the purple hose from the vacuum ball under the fender is the source to the solenoid programmer which is located behind the R/H side of the instrument panel, make sure it's connected and has vacuum for the system.
 

acoen

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An easy first check before digging into it too far. Make sure the vacuum hose hasn't come off at the firewall in engine compartment (behind and to the right of the coil pack). The hose connection has connection points one is for the HVAC Control the other goes to the EGR and the other somewhere else (possibly cruise control). If this comes loose you will only have defrost and underdash heating and cooling. Trying to eliminate the easy stuff first.
 

turbofish38

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Dec 3, 2002
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IIRC the system is self-diagnosing. Are any of the LEDS flashing. If they aren't than I would take Daves suggestion and look for a vacuum supply problem. If they are flashing than you have a control or programmer problem which isn't good becuase those parts are discontinued. Let me know. I have a link to a place that might be able to repair or rebuild them.
 

rb68rr

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Thanks for all the suggestions. I dropped down the glove compartment and could see some kind of connection that has eight different colored hoses that look like vaccuum hoses. Are they? Also at the top left behind the door, straight back from the trunk release button, I could put my hand in there and feel a lot of cool air coming from somewhere. I couldn't see where the colored vaccuum hoses went to. All the vaccuum hoses under the hood appear to be ok. Still confused. R.B.
None are flashing. Touch control seems to be ok.
 

jpratt

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May 6, 2004
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I had a problerm with mine and I replaced head unit and solenoid box. Got them from Brian at gbodyparts.com Expensive but soemtimes the only way to get it done.
 

turbofish38

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Dec 3, 2002
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Check your supply hose and the check valve out in the engine compartment. Back on the fire wall by the coil pack is a plastic check valve. They like to crack and leak vacuum. One of the hoses coming off that valve supplies the vacuum to the programmer behind the glove box.
 

rb68rr

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There doesn't appear to be any cracks in the plastic valve on the firewall. Took the hose off and it does have suction. Looking behind the glovebox with the motor running and the a/c on, when I increase the temperature on the climate control from 65 to 80, I can see the arm pivoting and the heater door closes. That's working off vaccuum isn't it? Folowed the blue vaccuum line that goes behind the climate control to it's source, whatever that is, and it's still connected. Still confused. Sorry. R.B.
 

salvageV6

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The defroster door vacuum motor is located behind the I/P on the LH side of the A/C plenum follow the blue vacuum hose it operates it.


You need to follow the blue hose to the destination which is below the source and at the end of the A/C plenum as noted above.

If it has vaccum on it make sure it's getting to that vacuum motor to operate it.

Pulling the radio out may help, or else you might want to remove the plastic trim from under the steering wheel two screws and a nut above the gas pedal will remove it to better see the vacuum motor to the left of the radio and right of the gas pedal.
 

salvageV6

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The source would be the vacuum switches in the control, you said you checked it there and never mentioned down below at the vacuum motor which is the destination or end, hence my comments.

If you have vacuum at the A/C defrost door vacuum motor on the blue hose you should have vent operation if it's working. Yes by all means check for vacuum at that valve in the A/C mode.

Possible problems could be bad vacuum motor not moving the door, jammed door inside the A/C plenum, or else the hose out of the plenum that feeds all the vents is off and the air isn't getting to them.

Another problem would be with A/C air coming out of the heater outlets, this should only happen on bi-level operation so make sure that switch is off when you do the A/C tests.

Theres 8 pages in the service manual regarding this system, decent pictures too.

Normal A/C which is NOT bi-level operation should only have the A/C air coming out of the vents, NOT the heater vent, therefore there could be vacuum valve or door operating problems on that part of the system as well.
 

salvageV6

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And just for informations sake, there are 4 doors that operate in the plenum for the system, A/C defrost door, Heater A/C door, temperature door, and the recirculating outside air door.

Sounds like you saw the temp. door moving which isn't either of the vacuum valves we are looking at right now.

Both vacuum doors are to the left of that temp. door.

Good to know that is working however. :)
 

rb68rr

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Boy, Am I getting more confused by the minute! Please excuse my ignorance. First of all what do you mean by the term "a/c plenum"? Second, I don't understand what you mean when you say "vaccuum switches in the control". Also air blows out of the heater vent when it's on econ, auto, bi-level, or defrost. If a door is jammed is there any way of manually un-jamming it, where ever these doors are? Thanks again, R.B.
 

salvageV6

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The A/C plenum is the large hard black plastic enclosure that houses the vacuum motors, vent/heat doors and has molded outlets for the heater, vents, defroster etc. all under the dash and out in the engine compartment to the heater water core, and A/C evaporator core, and blower motor, it provides the enclosed air chamber to run all that stuff.

It runs from the passenger door right vent all the way to the left of the radio area.

I believe the vacuum doors and motors we are looking for are under and to the left of the radio area down low, just above the heater vents for one and to the left of them for the other one with the blue hose.

Try removing that access plastic cover I mentioned, or the radio itself.

The source for the vacuum to each vacuum motor would be the vacuum solenoid programmer located in the glove box area just behind it.

The vacuum goes from that control unit out to the junction point behind the glove box door you found, then out of that point down to or over to each vacuum motor, water valve etc. that each hose runs.

Those hoses must be followed to their destination.

The other door, heater A/C mode vacuum door control uses two hoses the black and the yellow ones to go to it since it has 3 positions.

If you can remove the actual heater vent you could see the door perhaps residing in the plenum for the 3 position door which could be jammed.

That is not the blue hose door we were checking first however, again that is to the left of that point.

Follow those 3 color hoses down low and you should find their destinations.

How much air comes out of the defroster versus the heater vents???

If it's only a little bit that may narrow down the problem, if it's equal or more air than the heater vent please post that infor. as well.

A/C mode check bi-level OFF.
 

rb68rr

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First of all let me thank you for all of your time and expertise. I really appreciate it. The last explanation helped a lot. is the octapus looking connector behind the glovebox the vaccuum solenoid programmer you mentioned? With the a/c on high the air blows hard out the defroster and also the heater vent pretty much equally. Thanks, R.B.
 

salvageV6

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At the hose location what colors and how many hoses are they.

The book shows the hoses coming out of the vacuum solenoid programmer itself just behind the glove box, those hoses run to a two part mating connector which is most likely what you are describing as the octopus connector.

Should be 6 connections there, violet which is the vacuum source hose, then the blue, yellow, black hose which changes to red hose, white which changes to gray hose, and orange.

In normal A/C operation there should be vacuum on the blue and yellow hose and none on the black/red hose.

The output of the controller that should have the vacuum source out of the controller, would be the connector that has these six colors, purple, blue, yellow, black, white and orange. That is the source group of hoses, see if it matches the colors on your car and if you separate those hoses for testing use them to check for vacuum.


The destination hoses you could follow down to the vacuum motors would be the connector with the following hose colors, purple, blue, yellow, red, gray and orange.

Colors we are looking for to go to vacuum motors are blue to one motor, and the red and yellow hoses to the other one.

You want to see vacuum on the blue and yellow hoses for sure with A/C operation and NONE on the black hose that mates with the red one at that connector.
 

rb68rr

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You're not going to believe this! I was going down the road a few minutes ago with my 87 year old mother in the car when all of a sudden BAM!!!, this loud noise from under the dash. My mother nearly jumped out of her seat! She said "what was that?". I just smiled when the air started blowing ot of the vents. Unbelieveable! R.B.
 
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