Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 20 of 68 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I have a 1999 corvette equipped with a dual passenger climate control system. When you turn the air on, the drivers side is cool, but no matter what you do with the passenger side the air is always hot.So the passenger side climate knob does not work. In addition the mode and auto buttons do not work along with the display.Any ideas what is wrong? Where I can buy parts if I need them and how complex the repair is Thanks for any help !!!!
 

·
Premium Member
Joined
·
3,766 Posts
Your problem is likely linked to one of two components. It can also be caused by a passenger operating the temperature control knob too quickly. Either the HVAC controller itself is failing (possible) or the actuator for the passenger side is failing (also possible).

First pull the codes:
http://www.digitalcorvettes.com/forums/showthread.php?t=118113

Then look them up in that link. If someone has simply operated the control knob too quickly, you can reset the HVAC computer and the actuators. To do this, put the key in the ignition and in the on position, but do not start it. Then, remove the HVAC fuse found in the passenger footwell area behind the mat. Leave it this way for a couple of minutes and then reinstall the fuse. Start the car and see if you have any changes.

Come back and let us know which codes you find first so we can help further.

Edit: I must be having a senior moment as I did not adequately read your post. If you are having trouble with the display itself and its controls, it is like the HVAC controller itself. Definitely check codes first though.
 

·
Registered
Joined
·
606 Posts
I have a 1999 corvette equipped with a dual passenger climate control system. When you turn the air on, the drivers side is cool, but no matter what you do with the passenger side the air is always hot.So the passenger side climate knob does not work. In addition the mode and auto buttons do not work along with the display.Any ideas what is wrong? Where I can buy parts if I need them and how complex the repair is Thanks for any help !!!!
Common problem is cheap quality build and solder joints fail

Open the HVAC head cover and reflow the solder of the A41 resistor chips and then test to see if that solved the problem before putting console trim back on.
 

·
Premium Member
Joined
·
30,448 Posts
I have a 1999 corvette equipped with a dual passenger climate control system. When you turn the air on, the drivers side is cool, but no matter what you do with the passenger side the air is always hot.So the passenger side climate knob does not work. In addition the mode and auto buttons do not work along with the display.Any ideas what is wrong? Where I can buy parts if I need them and how complex the repair is Thanks for any help !!!!
You are having two common issues. First, post your codes. Then, let's address the dim display, because you must be able to see it in order to fix one of you other issues.

To fix the dim display, there are a bank of 8 resistors that you will need to reflow the solder on. Check out this recent thread for a DIY. Once you get the display working again, you need to tell us if your outside temperature reading is correctly. If not, your outside temperature T-stat is bad. This will cause the problem you are having where the auto mode button not working.

Gordon told you how to do a reset of the actuators, although I want to be a tad bit more clear. Here are the instructions from the service manual.

Re-Calibrating Actuators
Use the following steps to perform the calibration update:

1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC Control Module (fuse #27).

Important
The module memory will not clear if the battery positive voltage circuit fuse is installed in less than 60 seconds.



3. Wait 60 seconds.
4. Install the fuse.

Come back here when the display is working and we'll continue.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
climate control failure

I went to the fuse relay center, Fuse 27 was identified as a "spare". However I removed the 15 amp fuse for 5 minutes, it had no effect. The I.D. table in the fuse cover does not identify a fuse for HVAC. Am I looking in the wrong place?? ?Please help!!!
 

·
Premium Member
Joined
·
30,448 Posts
I went to the fuse relay center, Fuse 27 was identified as a "spare". However I removed the 15 amp fuse for 5 minutes, it had no effect. The I.D. table in the fuse cover does not identify a fuse for HVAC. Am I looking in the wrong place?? ?Please help!!!
Yes you are. You were in the engine. That is not where the fuse is located. It is located under the removable floor board on the passenger's side of the car.

By the way, welcome to DC. :buhbye:
 

·
Registered
Joined
·
6 Posts
Discussion Starter #7
found the panel but no cigar!

THANKS FOR YOUR HELP! I found the panel and fuse. I removed the fuse for 5 minutes and reinstalled it. But when I turned on the ignition I still did not get a display on the unit. I tried pushing the buttons without success. Any more suggestions, I greatly appreciate the help,THANKS DN!
 

·
Premium Member
Joined
·
30,448 Posts
THANKS FOR YOUR HELP! I found the panel and fuse. I removed the fuse for 5 minutes and reinstalled it. But when I turned on the ignition I still did not get a display on the unit. I tried pushing the buttons without success. Any more suggestions, I greatly appreciate the help,THANKS DN!
The fuse pulling instructions have nothing to do with the display. The fuse pulling are to reset the actuator doors and make the car blow the correct temperature on both sides of the car. That was one of the problems you were having, correct?

I posted a link to the instructions on how to fix the display. Go back and thoroughly read my earlier post (#4).
 

·
Registered
Joined
·
6 Posts
Discussion Starter #9
Inactive climate control/Junkman2008

I resodered the 8 #241 resistors and now my climate display works fine. However I am still getting hot air from my passenger vents. I also tried removing the HVAC fuse again without success.Junkman, I greatly appreciated your step by step directions, I am the type that needs those. I:buhbye: :buhbye: :buhbye: :buhbye: :buhbye: :buhbye: f you or anyone else who may have any ideas please forward them to me (detailed), I would greatly appreciate the help. THANKS TO ALL!
 

·
Registered
Joined
·
913 Posts
I don't have detailed information on this but it sounds like the air mix door actuator could be the problem. You will have to locate it and see if it is working when the temperature is changed.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #11
Climate control door actuator failure HELP!

Hoopty thanks for the info. but I need to know more about where this air mix door actuator is located, how to get it out and test it. Anyone with more info . I would greatly appreciate it.!!!!!!!!!!!!! DN
 

·
Premium Member
Joined
·
30,448 Posts
If you followed the instructions correctly for calibrating the actuators, then your passenger's side actuator could be bad. If that is the case and it needs to be replaced, it is not an easy job. The dash pad has to be removed in order to get to it. Is this a repair you want to attempt? If so, I'll post the directions.

Before you think about doing all that, you have never posted your codes as I requested before. You need to post your codes.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #13
junkman2008 Climate control codes

Junkman2008, Where is the plug-in for the computer located so I can read the codes? THX DN
 

·
Premium Member
Joined
·
30,448 Posts
Junkman2008, Where is the plug-in for the computer located so I can read the codes? THX DN
You don't need a computer to read the codes on a C5. You can read them from the DIC. How to do this and other important information about your car is located in the stickies at the top of this forum.

How to Pull Your Codes
 

·
Registered
Joined
·
521 Posts
there is a guy on ebay spedometer someting he rebuilds these for like $100.00 this happened to mine and i just sent him mine he sent me another and my problems went away
 

·
Premium Member
Joined
·
30,448 Posts
There's no rebuilding to them. The only thing that goes wrong with them are the resistors developing cold solder joints or some of the LED's going out. Definitely not worth $100 to fix if you can solder and remove the unit from the car. There are enough instructions on this forum alone that make it a very easy fix.

The problem the OP is experiencing is very common as far as the display is concerned but the climate control issue has nothing to do with the unit. That's a recalibration issue or one of his actuators has failed (possible but not a high failure rate part). The codes will help evaluate the exact situation but a recalibration is most likely going to fix the hot/cold air issue. Mine did it last week and I fixed it while driving down the road.
 

·
Registered
Joined
·
196 Posts
Reviving an ancient thread since I'm now experiencing this with the C5 I bought a month ago.

Junkman: My driver's side vents are blowing hot, but the passenger side is blowing cold. I followed your instructions but no HVAC codes came up before or after the HVAC fuse yank and reset.

Does the driver's side actuator give a code when it's not working?
 

·
Premium Member
Joined
·
30,448 Posts
... Does the driver's side actuator give a code when it's not working?
Yes it will, but you may not have an actuator problem and thus, will not throw an actuator code.

Here's what you need to do. Find a mom and pop shop that has a evac and recovery machine for AC system. Tell them that you want to do a evac and recovery but the MOST important thing you want to get from the process is EXACTLY how much R-134a you have in your system presently. This is extremely important in trouble-shooting your issue. Your system should have exactly 0.737 kg (1.625 lbs, based on a 1999 dual climate or manual system). If there is a lower amount of refrigerant in your system then you know that you have a leak. This will also explain why you are experiencing the condition that your are experiencing.

What they will need to do is refill the system and inject some green dye while refilling. Make sure they do that. The green dye is very important because that is how you are going to locate your leak. You can get a dye checking flashlight at any auto store for cheap. Depending on how fast the leak is, you are going to check your AC lines every other day to see if any green residue appears on the outside of the line. If it does, you have just located the leak. The area that I would keep an eye on is the compressor itself. You want to check all around that puppy. You will have to remove the passenger's side wheel in order to get a real good look at it. If you still have cold air after a week, that's when I would pop the tire off and check the compressor. If the problem comes back, then you definitely need to pull the tire and check ALL the lines and the compressor.

Don't pull the bush league shade tree mechanic's route and just dump more R-134a into your system. Too much or too little R-134a can create this issue and then some. The evac and recovery will cost you anywhere from $50 to $100 plus the amount of R-134a needed to get your system up to the right level so shop around. Don't go to the dealership unless you have to. They will want $130 or higher.

The key to resolving this issue is proper trouble-shooting. I've seen some horrible advice given on this issue and from all the experience and research that I did on resolving mine and others, I would put my advice up against anyone's.

Make sure you report back and let us know what you find. :thumbsup:
 
1 - 20 of 68 Posts
Top