1. AC resets itself to auto each time I turn off the ignition.
2. AC blows cold but every 30 sec or so it cycles the diverter door to the hot side for a sec or 2 then moves back. It never gets hot just 10 to 15 deg warmer during the cycle.
3. When in Auto, the compressor is working but the blower fan speed stays on 0 no matter where I set the temp. I can manually override it by using the fan speed up button and get it to work. The up/down buttons work just fine. If I set the fan speed to auto it stops blowing again. The temp control seems to work just fine for controlling air temp just not the fan speed.

The climate control system is not throwing any codes.

The radio holds its memory I don't understand why the climate control doesn't.

I appreciate any light you can shine on this!!

 

What year is the car? The system was completely redesigned in 1990, so it make a huge difference.

You might have a blown fuse or a bad connection. My car's CTSY/CLK fuse maintains the memory in the HVAC system.

Does the diverter door recalibrate when the ignition is first turned on? If it does, that indicates that the HVAC system lost power when the ignition was turned off.

 

Sorry about that!
1996

 

I had similar issues with my 96 Coupe when I first got it....it was like the climate control had a mind of it's own, although I could usually overide the auto selection sometimes it would freeze your feet for a few minutes....before diverting to full defrost....and then eventually get around to blowing out of the vents like a good girl.

I fixed it by removing the center console and faceplate for the radio / heater section ( there is a small Torx screw in the upper vent left hand portion that hides very well ) after you get the pretty parts off the heater control is held on by four ( I think ) phillips screws. Take those out and the heater control will come out easily. There is a vaccuum manifold on the backside of it that I thought was the culprit but all was intact.
My problem was dirty contacts on the buttons...if you have ever taken a TV remote control apart you will find this very similar with a rubber mat under the plastic button that you see from the front.
Beware that behind this mat are small springs for each button so don't flip it upside down.

I used some electrical contact cleaner from CRC and followed up with an eraser from a number two pencil, cleaned the rubber mat and re-assembled the pig.

It's still working but I think it might be time to go after it again as it's gettin a little slow to shift sometimes....like a lot of things on these cars regular use makes the problems go away, when I took the car to Bowling Green and drove it every day for a week and a half on vacation..it worked as good as new every time.

later, tiny

 

I saw that problem when I did a search. All of the buttons function. The auto button shows me 0 for fan speed when I press it. If I have the fan blowing on manual and I press auto it turns them off and shows 0. I don't believe it is a vacuum issue either because the diverter valve moves between cold and hot when I adjust the temp. All of the fuses are good.

Is there a separate wire that goes to the ignition (or hot all of the time) that would keep the memory only for the climate control?

 

Off the top of me head ....I don't know, all the problems i've ever had were due to low voltage ( crap battery ) or dirty connections. Sorry not much help.

later, tiny

 

The temperature blend door is controlled by an electric motor.

Possibly, on your car. On my relatively ancient Corvette the memory for the dash, HVAC and radio are all powered by the CTSY/CLK fuse.

 

My, 96 c4 blows cold in the winter and hot in the summer, i know that it has 3 temperature sensors, but don't even know if that is the problem.

Now it it has a short in the headlight switch circuit, when i turn on the parking lights or the headlights the headlight actuator arms rock back and forth violently,

and does the same when i turn the switch off, help!!!

 

294,, i just fixed this exact same problem on my 96.. Doing the exact same thing,,always went to fan speed 0,, and would blow warm air for 10 sec or so , then go back cold.. My issue was the blend door actuator. I changed it out and it fixed the issue .. When i took the old one apart . A gear on the inside was cracked ,allowing it to slip on the shaft.

 

Another Zombie thread!