computer climate controle

i have a 1998 Gmc jimmy and i recently had to replace the battery the old one had a bad cell. the problem now is that the a/c will only blow heat it has the proper amount of 134 and the com pressor works fine. i hear a noise under the dash that sounds like a door in the duct work is oppening and closing. it tries to blow cold but only for a few seconds and it comes in cycles.

i have a 1998 Gmc jimmy and i recently had to replace the battery the old one had a bad cell. the problem now is that the a/c will only blow heat it has the proper amount of 134 and the com pressor works fine. i hear a noise under the dash that sounds like a door in the duct work is oppening and closing. it tries to blow cold but only for a few seconds and it comes in cycles.

not sure i know some of the models you can recalibrate the mode door actuator dont know if the aftermarket scan tool can do it dealer scanneer does.

Thanks. I will try.

I own a 2000 with the auto climate control. I wound up having to replace the head (dashboard contol) unit. The door you are hearing is located beind the glove box. You can actually watch it move as you change modes to see if it is working. If the problem is on the control side of the airflow, then it is very difficult and expensive to get the door that controls the air flow across the heater coil. It would have been a lot simpler if they stayed with the valve and contolled water flow to the hetaer core, but in this system, they control airflow across the heater core, thus setting temperarure. Pray that it is the control unit.

I had to replace my battery and have the same exact problem...what can we do?????

Did anyone ever figure this out? I have the exact same problem. There is a door going crazy in my dash open close hot cold nothing. I don't remember if it did it before I replaced my battery or not 2 weeeks ago

i have the same problem. I stopped at a automotive store and the guy behind the counter (and i always take what they say with a grain of salt) said it is probably the body control computer (BCM) i havent tried replacing it because even the cheap ones are 100 bucks and need to be programmed by the dealer. anyone know if this would work and if its worth the money and/or would a junk yard one work without reprogramming

i have a 1998 Gmc jimmy and i recently had to replace the battery the old one had a bad cell. the problem now is that the a/c will only blow heat it has the proper amount of 134 and the com pressor works fine. i hear a noise under the dash that sounds like a door in the duct work is oppening and closing. it tries to blow cold but only for a few seconds and it comes in cycles.

Hello, I'm having the same noise coming from my dash. Did you ever het yours fixed? and if so what did you do? Any help would be appreciated... mine is a 1999 jimmy 4x4.
Thanks , Tim Bushong
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