Hello, I have a 1998 Base Model Corvette with an AC problem that I can't figure out. I know this topic has been beat to death over the years, but I can not find an answer to my issue. I do have dual climate control.

1) Like most I had hot on one side and cool on the other. I replaced both blend door actuators. Yes, both had broken gears, I opened them to see. Still not fixed.

2) I took the car to a shop and after about an hour I was told the whole AC unit needs replaced. They said the high and low pressures where too far apart.

3) I replaced the AC compressor, the condenser, the filter drier and the expansion valve. I flushed out the evaporator and all lines. After holding a vacuum for 24 hrs I refilled with freon. I filled it by weight as best I could. I then added a little more freon based on a pressure chart. I have been trained in AC repair and the job was done right.

4) Nice cold air until I change the temp. As I turn it to a warmer temp it seems to work fine. However when going back to cooler temps, it will not get cold again. It does cool down some but the air is still warm. If I only change the passenger side the problem is only on the passenger side. If I change the driver side the problem is on both sides as expected. When this happens I get codes. When I clear the codes the actuators cycle from hot to cold the codes come back and the air goes back to hot. The codes I get are B0361, B0367, B0441 and B0446. It could be any 1 of these codes or maybe 2 or 3 or all 4. When the codes come some may be H some may be C and some may be H C they change every time but these are the only codes I ever see.

5) The only way I have found to resolve this is to clear the codes then, as soon as the air gets ice cold, turn the car off. When the car is restarted the air will be cold and no codes will appear. This is done with the air set to 60 degrees and the passenger side set in the center. If I change the temp, same problems reoccur.

6) I have tried pulling the fuse for 1 min. It doesn't help. I have left it out for more than 60 seconds still no help.

My question is, could this be a faulty Climate Control Unit? Or what else could it be? My Climate Controle Unit does have the problem with dim light. I believe that is a separate issue, though I could be wrong. I hope someone will have some insight on this issue and I would appreciate any help I can get. I hope I have given enough info but if more is required please let me know.

 

The DTC’s you’re seeing can either be bad actuators, wiring, or the HVAC control head…if your not confident in your electrical skills I’d go and replace the control head since the actuators were already replaced…having a factory level scan tool to observe some HVAC data PIDS would help.

 

C5 Diag, thank you for responding. I did think of the wiring and maby some loose connections. I'm just not sure where to look, other than the actuators and the back of the control head. I thought I need to replace the control head I just wanted to ask before doing so.
I don't have a scan tool other than the cheap Bluetooth dongle type. And I don't think they would be any more helpful than the DIC.
So, I guess I will replace the control head and go from there. I believe these can only be purchased used or do you know of a place to get a new replacement?

Thanks again.

 

You will not be able to purchase a new OEM but if you Google you can find some that are used or refurbished…there are companies that can repair your current one…your code reader or DIC will only be able to retrieve codes…with a factory level scan tool you can look at the HVAC module inputs and outputs.

 

This is how you would diagnose your B0361.

 

Yes, that's what I thought. I've been looking for one for about 2 weeks now. I wish I had a scan tool but it will be a while before I'm in a position to buy one. Same for the head unit. At least I can drive the car now as long as I don't change the temp. I don't think I've put 100 miles on it in the 3 years I've owned the car. It was just too hot. I was looking at Zip Corvette they offer a rebuild service for around $190. I'm just not sure if it only addresses the dim light issue or repairs the whole unit. I'm planning to call them tomorrow to find out.
Thanks for your help.