1990 ac controls
Thread Starter
Instructor
Joined: Jun 2006
Posts: 164
Likes: 0
From: tullahoma tn
1990 ac controls
i have the climent control everything seams to be working but the air is not getting as cold as it should and it has no heat is the controls bad or do i need to look somewhere else thanks
Burning Brakes
Joined: Jul 2004
Posts: 806
Likes: 0
From: Langley B.C.
Could be the door for the heater is not opening /closing properly.Someone with your system will be able to tell you how to put it in diagnostic mode or use the search system to find out how to do it.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Cold air is a function of charge - it's got to be full of refrigerant and you might want to have that checked. Otherwise, a temperature door allows air that's been warmed by the heater core to mix with the cool air depending on the temperature selected at the controls. If that door is stuck or not moving, you might get warmer or colder air than what's been selected. To check it out, remove the Blower Module on the left side of the Evaporator Case and look inside to see the door. Have someone operate the Controls and the door should move between 60 and 90. If not, see if you can move it manually. If so, a plastic connector holding the linkage to the electric motor that controls it has probably broken. Access from the passenger compartment after removing the hush panel.
If you have no heat, the heater core may be plugged up. The '90 provides coolant to the core at all times and once it's clogged up, the coolant flows over the top of it, but not through it. You can try to flush it by disconnecting the hoses and hooking up a garden hose or use compressed air. Go easy on the pressure as system pressure is less than 20 psi.
If you have no heat, the heater core may be plugged up. The '90 provides coolant to the core at all times and once it's clogged up, the coolant flows over the top of it, but not through it. You can try to flush it by disconnecting the hoses and hooking up a garden hose or use compressed air. Go easy on the pressure as system pressure is less than 20 psi.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
The only way to know if the system has the enough refrigerant and that it's moving through the system unobstructed is to obtain operating pressures. If you have those, you might post them.
The door you need to observe is on the opposite side of the Evaporator Housing or the part that juts out from the Firewall. On the left side there is a Module bolted to the top of it. Remove that Module and look inside to observe the temp door.
The door you need to observe is on the opposite side of the Evaporator Housing or the part that juts out from the Firewall. On the left side there is a Module bolted to the top of it. Remove that Module and look inside to observe the temp door.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
35 to 40 on the low translates to mid 50's air. If it's 90 to 95 degrees that's probably ok, but if it were mine, I'd try and tweak to 28 -32 psi, particularly for the summer. I'd also make sure the high is no more than 2.2 to 2.5 the temp of the air at the condensor. Hopefully you sucked all the air out of it. Pull the Module and see what the temp door is doing.
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Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Have a looksee at this thread and especially the really good pic in post #2 taken by brookman
http://forums.corvetteforum.com/show...highlight=door
http://forums.corvetteforum.com/show...highlight=door