HVAC issue 1994 C4
Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 800
Likes: 45
From: San Diego CA
HVAC issue 1994 C4
I've had the a/c issue for a while and haven't been able to figure it out yet. One thing I have noticed is, when the weather is very hot outside the a/c won't blow cold. When weather is normal or cool, it works just fine. Sound like something is causing the a/c to have high pressure I'm thinking.
Is there an air filter in these cars? I'll start there.
Is there an air filter in these cars? I'll start there.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Your temperature blend door might have a problem. Remove the resistor network (C60) or blower control module (C68) from the evaporator housing in the engine compartment and look into the opening. You will see the rusty blend door (they're always rusty for some reason).
Set the HVAC temperature to minimum and check the position of the blend door. It should be blocking the heater core.
Set the HVAC temperature to maximum and look at the blend door. It should block the opening into the HVAC ducts and leave the heater core exposed.
Set the HVAC temperature to minimum and check the position of the blend door. It should be blocking the heater core.
Set the HVAC temperature to maximum and look at the blend door. It should block the opening into the HVAC ducts and leave the heater core exposed.
Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 800
Likes: 45
From: San Diego CA
Your temperature blend door might have a problem. Remove the resistor network (C60) or blower control module (C68) from the evaporator housing in the engine compartment and look into the opening. You will see the rusty blend door (they're always rusty for some reason).
Set the HVAC temperature to minimum and check the position of the blend door. It should be blocking the heater core.
Set the HVAC temperature to maximum and look at the blend door. It should block the opening into the HVAC ducts and leave the heater core exposed.
Set the HVAC temperature to minimum and check the position of the blend door. It should be blocking the heater core.
Set the HVAC temperature to maximum and look at the blend door. It should block the opening into the HVAC ducts and leave the heater core exposed.
Instructor
Joined: Nov 2006
Posts: 173
Likes: 7
From: Blk Mtn NC
Try disconnecting the battery for a few minutes and reconnect or remove the HVAC fuse in the passenger's side panel. Either way what you are doing is a hard reset on the HVAC controller and the servo blend door so it relearns it's position. Do not try moving the door by hand bad things will happen.
Since 1996 I have done this about 3 times when I've had a similar problem and it fixed it.
Good luck.
Mike
Since 1996 I have done this about 3 times when I've had a similar problem and it fixed it.
Good luck.
Mike
