Air Conditioning Problem

[Five Point 5]

Sometimes the AC blows warm of hot air out of the passenger side vents even when the systen is set to A/C, max cold at the control, and max cold of the passenger side. At other times, the system works correctly. No codes.
Any suggestions?

[luk3r]

Originally Posted by Five Point 5

Sometimes the AC blows warm of hot air out of the passenger side vents even when the systen is set to A/C, max cold at the control, and max cold of the passenger side. At other times, the system works correctly. No codes.
Any suggestions?

I have never heard of this on a vette..BUT..sometimes the expansion valve in the A/C train freezes over, hence not being able to cool air. But that generally affects the whole output, not just half the car *shrug*

[Kanon]

I'm going to be vague because I haven't had the problem yet.. but there's an actuator that switches between the heater and A/C. Its known to have calibration issues and sometimes break. This will cause symptoms like you describe. Sometimes a code will be thrown, but not always. If you search around, you should be able to find instructions to force the computer to perform a calibration routine and replacement instructions (if necessary).

Update:
Here's a thread with the calibration init methods:
http://www.digitalcorvettes.com/foru...light=actuator

[oscarmanny]

Luk3r I think "I have never heard of this on a vette..BUT..sometimes the expansion valve in the A/C train freezes over, hence not being able to cool air. But that generally affects the whole output, not just half the car *shrug*" is exactly my problem. How can I fix this?
thank you

[T.M.]

Sounds like the classic c5 actuator issue.

[Junkman2008]

Originally Posted by oscarmanny

Luk3r I think "I have never heard of this on a vette..BUT..sometimes the expansion valve in the A/C train freezes over, hence not being able to cool air. But that generally affects the whole output, not just half the car *shrug*" is exactly my problem. How can I fix this?
thank you

Welcome to DC.

Do you realize that your first post was a response to a thread that is over two years old?

What year Corvette do you have? According to your profile, you have a C4. I don't think this problem affects a C4. You're posting in the C5 section. So do you have a C5?

[solo25]

Junkman, first, thanks for your help to me and everyone in the past. I've been having the same a/c problems as others, (hot drivers side/cold passenger) for a couple of years. My car is a 2003 C5. I've lived with it by resetting the actuator by removing the fuse, and recently, just clearing the codes manually on the DIC. Have you ever heard of this?.... when the a/c in on, motor running, and the air is hot on the driver's side, I bring up the codes. As I scroll down through them to HVAC, and hit reset, I can actually hear the door opening in the dash and cold air will come out. I'll usually have to do this several times before it "sets" and cold air continues to come out without resetting the codes. Then it will be good for a long time, or until me or someone else turns the temp control knob on the driver's side to warmer. That causes the problem to start again.

OK, now for the fix part. I'm taking my dash apart anyway to upgrade my stereo system, so if you agree that it is the acutator that is bad, I will replace it while I'm in there. Unfortunately, back when I first started having the problem, I bought a replacement actuator for the day that I would do this job. I've put it off until now. Problem is, it's the old style actuator, without the stops, so I'm wondering if it's worth putting in. I was looking at it, and wondered if I could make a couple of stops on it to simulate the newer parts. If I have a 2003, wouldn't the original part have the stops? I bought the part from Gene Culley, and he has always been good when it comes to the right part.

sorry for the long post, any help would be appreciated. By the way, the codes have always been B0331 and B0441.

Thanks,
Mike

[Junkman2008]

First off, the actuators without stops were discontinued after the 2000 year model so you definitely have the wrong part. Second, you can't fix the problem until you know what the problem is. If you have read my many post on this subject, you would know that your first step is to find out how much R-134a you have in your system. The amount is EXACT. That's ALWAYS step one. It seems that everyone tries to avoid this step and start doing shotgun repairs by replacing stuff when that is a totally illogical approach to me. If I do something to fix the car, I don't want to have to go to a plan B. Plan A will always work if you correctly trouble-shoot the issue.

With that said, you should have exactly 1.75 lbs (0.79 kg) of R-134a in your system. You need to find a mom and pop shop that can evacuate and recover your R-134a. They need to be able to tell you EXACTLY how much was recovered. If it is LESS than the amount you are suppose to have, then you have a leak. They need to refill it to the exact amount while injecting the green dye into your system. You will use a special light to inspect your AC lines once the problem occurs again in order to locate the leak.

If the R-134a is not low, then the problem resides elsewhere. Either the actuator or the HVAC unit itself are the most common failures. One thing that you need to ensure is that YOU are not causing the problem yourself by turning the temperature knob too fast in any direction. If you spin that knob too fast, the HVAC unit may not be able to interpret the action and can throw the system out of whack. Another thing that you can check is to make sure that there are no software upgrades that were issued for your car concerning this issue. Only a GM dealership can give you this information.

The good news for you is that you don't have to remove the dash pad in order to replace the left actuator (you do for the right side). So the job isn't bad but I wouldn't put the actuator that you have in your car. That could actually cause more issues later on that may require a complete disassembly of your dash if the actuator damages the door that it opens and closes. That would suck donkey balls. So if the actuator is the culprit, fix it with the correct part.

So you need to start with step one. Let me know what you find.

[solo25]

I've had the refrigerant removed, weighed and replaced with dye. Everything looks good. As I said in my previous post, I already have my dash out. I'm looking at the guts and I have a question. What you have been calling the actuator is called the controller on the Gene Culley parts diagram. The actuator is the round thing that is flat on one side and has an arm with an hole to connect it to. So are we talking about replacing the actuator or the controller?

[Junkman2008]

This is the actuator. It is the same exact one that should be in your car. You have to drop the knee bolster (not the dash pad) to get to the one on the driver's side of the car. The dash pad has to come off to get to the passenger actuator.

[solo25]

OK, that's what I thought. The confusion happened when I went to the GM Parts site.

http://store.gmpartshouse.com/parts/...iagram=CF97045

As you can see, they call part 21 the Controller, which is the part you pictured, and part 14 the Actuator, which is what I was talking about. Since I already had the dash off, I removed the part from the top (driver's side). Honestly, I don't see how you could do it without removing the dash.

[Junkman2008]

That's why you want to have the service manual when doing in-depth work like this on your car. The proper way to do this is to go through the IPC. Also, Gene's chart has those two parts labeled wrong. Part #21 is the actuator. The part labeled #14 is called the mode actuator. You can see this in the attached instructions.

[solo25]

So I don't need to replace the mode actuator, right? That is not what is sending the trouble codes, I'm guessing.

[Junkman2008]

Originally Posted by solo25

So I don't need to replace the mode actuator, right? That is not what is sending the trouble codes, I'm guessing.

That is not a common failure part, however, I would need to trouble-shoot your issue with a Tech II in order to say that it is definitely not the problem. With that said, if your R-134a levels are exactly where they should be, I would tell you to double-check EVERYTHING that I posted in post #8. Read it again.

Another thing, have you done any work to your HVAC unit?

[solo25]

Thanks Junkman. OK, here's where I am now. I ordered the new actuator from Gene Culley. When it arrived, it looked like the old design (no metal stop). I called him up and spoke to him, and he said that the part he sent WAS the latest design, redone in 2004. I believe him, but I sent him a copy of your post and pictures of the old (the one out of my car) and new (received from GMParts) actuators. I am a little leery about installing the new part until I'm sure it's right. What do you think? The number on the new part is 89018365.