Heat and AC Controls...
Thread Starter
Drifting
Joined: Sep 2007
Posts: 1,391
Likes: 377
From: Cincinnati Ohio
Heat and AC Controls...
Hello All,
In the past few months I have been having spuratic problems with my heat and AC controls. This morning on the way to work I tried to raise the temperature to give me some heat. I could lower the temp but I could not raise it at all. The on\off and fan controls would work but nothing else....When I got in it to come home this afternoon everything was fine...I could raise and lower the temp and everything worked as it should.....What gives?? Anyone else had this problem?
Thanks In Advance
In the past few months I have been having spuratic problems with my heat and AC controls. This morning on the way to work I tried to raise the temperature to give me some heat. I could lower the temp but I could not raise it at all. The on\off and fan controls would work but nothing else....When I got in it to come home this afternoon everything was fine...I could raise and lower the temp and everything worked as it should.....What gives?? Anyone else had this problem?
Thanks In Advance
Team Owner
Joined: Oct 2000
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From: Fort Knox, KY
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You've got a '94 right? First, check the plastic check valve under your fuel rail cover. I think it's on the passenger side. It could be cracked, resulting in a vacuum leak in the climate control unit. I believe it shares the same line that enables your cruise control module, too.
Le Mans Master
Joined: Mar 2004
Posts: 8,700
Likes: 298
From: Ft. Lauderdale Fl
You've got a '94 right? First, check the plastic check valve under your fuel rail cover. I think it's on the passenger side. It could be cracked, resulting in a vacuum leak in the climate control unit. I believe it shares the same line that enables your cruise control module, too.
and sells for under $5.00.
Last edited by runner140*; Aug 13, 2009 at 07:56 AM.
Thread Starter
Drifting
Joined: Sep 2007
Posts: 1,391
Likes: 377
From: Cincinnati Ohio
You've got a '94 right? First, check the plastic check valve under your fuel rail cover. I think it's on the passenger side. It could be cracked, resulting in a vacuum leak in the climate control unit. I believe it shares the same line that enables your cruise control module, too.
thought I would need HEAT in JULY!!!! I will check this part..
My cruise works great..
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Hello All,
In the past few months I have been having spuratic problems with my heat and AC controls. This morning on the way to work I tried to raise the temperature to give me some heat. I could lower the temp but I could not raise it at all. The on\off and fan controls would work but nothing else....When I got in it to come home this afternoon everything was fine...I could raise and lower the temp and everything worked as it should.....What gives?? Anyone else had this problem?
In the past few months I have been having spuratic problems with my heat and AC controls. This morning on the way to work I tried to raise the temperature to give me some heat. I could lower the temp but I could not raise it at all. The on\off and fan controls would work but nothing else....When I got in it to come home this afternoon everything was fine...I could raise and lower the temp and everything worked as it should.....What gives?? Anyone else had this problem?
Here is a brief summery of how things works. The head sends input to the controller which then operates the vents and the temperature door motor. The temperature door is what controls the air temperature coming in to the (system) car. The problem is you are not able to control the temperature door motor. But it sounds like your main problem is your control head is not working correctly. You should be able to run the temperature up to 90* regardless of anything else. If you can’t control the “head”, then you can’t control the controller or the door motor.
Inside the head is 2 boards that are joined by a multi-pin connector. You might try to disassemble unit and clean the pins as well as the pins on the rear of the unit with alcohol. Always dry things well before re-assembly. Other that that the head might just be defective. If that is the case it might have to be replaced.
Thread Starter
Drifting
Joined: Sep 2007
Posts: 1,391
Likes: 377
From: Cincinnati Ohio
In no way is this the 3 way check valve causing your problem. I have had my own similar problems the last few weeks and have done extensive work on the system and not done yet or ready to post my own results.
Here is a brief summery of how things works. The head sends input to the controller which then operates the vents and the temperature door motor. The temperature door is what controls the air temperature coming in to the (system) car. The problem is you are not able to control the temperature door motor. But it sounds like your main problem is your control head is not working correctly. You should be able to run the temperature up to 90* regardless of anything else. If you can’t control the “head”, then you can’t control the controller or the door motor.
Inside the head is 2 boards that are joined by a multi-pin connector. You might try to disassemble unit and clean the pins as well as the pins on the rear of the unit with alcohol. Always dry things well before re-assembly. Other that that the head might just be defective. If that is the case it might have to be replaced.
Here is a brief summery of how things works. The head sends input to the controller which then operates the vents and the temperature door motor. The temperature door is what controls the air temperature coming in to the (system) car. The problem is you are not able to control the temperature door motor. But it sounds like your main problem is your control head is not working correctly. You should be able to run the temperature up to 90* regardless of anything else. If you can’t control the “head”, then you can’t control the controller or the door motor.
Inside the head is 2 boards that are joined by a multi-pin connector. You might try to disassemble unit and clean the pins as well as the pins on the rear of the unit with alcohol. Always dry things well before re-assembly. Other that that the head might just be defective. If that is the case it might have to be replaced.
I will have to look into the connection in the back and do some cleaning on the electrical connections.
3rd Gear
Joined: Aug 2009
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Le Mans Master
Joined: Aug 2000
Posts: 8,838
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From: Australia
Many have has success by removing the rubber button pad and cleaning the contacts underneath with alcohol
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Le Mans Master
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From: Ft. Lauderdale Fl
Melting Slicks
Joined: Mar 2008
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From: Delta B.C. Canada
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What and where exactly is this "control head"?
Same question re the "rubber button pad".
Same question re the "rubber button pad".
Pro
Joined: Mar 2008
Posts: 579
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From: High Bridge New Jersey
Le Mans Master
Joined: Jan 2006
Posts: 5,621
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From: Orlando FL
The controller is up underneath kind of above the gas pedal where you can’t see it. I agree the terms are confusing, GM should have completely different names for the units.
RODJ – Also has a good added suggestion for that problem (that I forgot). You do have to take apart the unit to get to clean the buttons.
Last edited by pcolt94; Aug 13, 2009 at 11:57 AM.
Instructor
Joined: Jul 2008
Posts: 178
Likes: 4
From: Chandler AZ
I had problems with those buttons also.
This was the cure:
Take the controller out of the dash. Take it apart (just some screws), and find the rubber pad that sits under the buttons. Under that rubber pad there are electrical contacts. I cleaned those by dipping a pencil eraser in alcohol and kind of scrubbing them. You won't really see any difference, it won't look any cleaner. I put it all back together and the buttons all work perfectly again.
This was the cure:
Take the controller out of the dash. Take it apart (just some screws), and find the rubber pad that sits under the buttons. Under that rubber pad there are electrical contacts. I cleaned those by dipping a pencil eraser in alcohol and kind of scrubbing them. You won't really see any difference, it won't look any cleaner. I put it all back together and the buttons all work perfectly again.
Melting Slicks
Joined: Mar 2008
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From: Delta B.C. Canada
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It's the unit that you control and set with the buttons on it above the radio. Such as fan speed and temperature, that is the control head.
The controller is up underneath kind of above the gas pedal where you can’t see it. I agree the terms are confusing, GM should have completely different names for the units..
The controller is up underneath kind of above the gas pedal where you can’t see it. I agree the terms are confusing, GM should have completely different names for the units..
Thanks. I've just never heard it refered to by that name.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Correction:
Got to say you are technically right. I strayed a bit on my terminology.
The control head is called the control head.
But what I called the controller, is really the programmer. Which is the unit under the dash. I think it could be a better name but that is the official one.
Got to say you are technically right. I strayed a bit on my terminology.
The control head is called the control head.
But what I called the controller, is really the programmer. Which is the unit under the dash. I think it could be a better name but that is the official one.
Thread Starter
Drifting
Joined: Sep 2007
Posts: 1,391
Likes: 377
From: Cincinnati Ohio
I had problems with those buttons also.
This was the cure:
Take the controller out of the dash. Take it apart (just some screws), and find the rubber pad that sits under the buttons. Under that rubber pad there are electrical contacts. I cleaned those by dipping a pencil eraser in alcohol and kind of scrubbing them. You won't really see any difference, it won't look any cleaner. I put it all back together and the buttons all work perfectly again.
This was the cure:
Take the controller out of the dash. Take it apart (just some screws), and find the rubber pad that sits under the buttons. Under that rubber pad there are electrical contacts. I cleaned those by dipping a pencil eraser in alcohol and kind of scrubbing them. You won't really see any difference, it won't look any cleaner. I put it all back together and the buttons all work perfectly again.
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
I called NAPA, Advance Auto Parts, and AutoZone and NONE of them had access to the part.
Called a dealer, had it for $2.45.
You would think something so simple would be readily available..kinda like candy bars.
Pro
Joined: Mar 2008
Posts: 579
Likes: 2
From: High Bridge New Jersey
Right
Thread Starter
Drifting
Joined: Sep 2007
Posts: 1,391
Likes: 377
From: Cincinnati Ohio
I had problems with those buttons also.
This was the cure:
Take the controller out of the dash. Take it apart (just some screws), and find the rubber pad that sits under the buttons. Under that rubber pad there are electrical contacts. I cleaned those by dipping a pencil eraser in alcohol and kind of scrubbing them. You won't really see any difference, it won't look any cleaner. I put it all back together and the buttons all work perfectly again.
This was the cure:
Take the controller out of the dash. Take it apart (just some screws), and find the rubber pad that sits under the buttons. Under that rubber pad there are electrical contacts. I cleaned those by dipping a pencil eraser in alcohol and kind of scrubbing them. You won't really see any difference, it won't look any cleaner. I put it all back together and the buttons all work perfectly again.
