Help! 98 corvette a/c problem

[Junkman2008]

... I now have another issue: my alarm function doesn't work. Could this be due to the pulling of fuse #27? My remote is less than a year old and the car is driven less than occasionally.

You need to start a new thread for a different problem.

 

[xdmikey]

Thank you for the direction.
I got it fixed.

 

[JamesB]

98 Corvette Bad Driver side HVAC Actuator

And there is exactly where so many people go wrong with trying to diagnose their AC issues. These cars do not work like your dad's 78' Buick. My gauges showed that my system was fully charged but when I used a ACR 2000 to check the actual freon amount, my car showed .4lbs of R-134a. I should have had 1.5lbs. This discrepancy was all it took for my system to do exactly as yours is doing. Once I added the correct amount of refrigerant, the system worked flawlessly

Now since you have a 1998, you are looking at the possibility of 2 different failures. The failure of leaking R-134a as mentioned above or the failure of one of your actuators itself. On the 1997-2000, there was an issue with the actuators going past the allotted ranges that they are designed to work in. In 2001, GM changed the actuators design by adding physical stops to them so that the actuators could not go out of range. For the 1997-2000 models, the service manual has you open the actuator up and adjust the gears slightly in order to get the actuator back into spec. If that didn't work, they had you replace the actuator with the newer design. Not a cheap fix that is as those actuators can run close to $300. The actuators are the devices that open and close the doors inside the dash, which allows hot or cold air to come through the vents. There are 2, one on the driver's side and one on the passenger's side. The driver's side can be removed without removing the dash. The passenger's is another story.

Here is a newer actuator with the built in stops. The actuator on your car does not have these right and left limit stops and thus, the actuator can get out of range.

If your system is low on R-134a, then you have a leak as the AC system is sealed. I covered how to replace the various parts of the AC system in this thread. If you have the correct tools, it is not too bad of a job. It will bust your knuckles though.

Hey Junkman, Your videos are the best, watched many times.
In response to this thread: After many hours researching and reading forums I believe I have a bad drivers side HVAC actuator, I've tried the reset procedures a couple of times with no correction but I don't have any DIC HVAC error codes. I want to make sure I get the right part with the limit stops and I have a few questions;

• I see actuators for $25.00-$200.00 so I'm a little confused
• Do you know of a part#/distributor for a replacement left side actuator with the limit stops for my 1998 C5 Corvette with the dual zone climate controller?
• Are the left and right side actuators the same part?
• Just wondering if the problem could be something else?
• Can I actually replace the left side actuator without removing the dash?


Any help would be greatly appreciated, here's the thread I posted yesterday;
JamesB

[h=2]1998 C5 HVAC problems[/h]

The front defroster in my 1998 C5 Corvette doesn't blow air on the driver's side so it fogs up. I removed the HVAC fuses (18 & 27 and 27 by itself) to reset the actuator but it didn't correct it. I could hear the actuator moving after replacing the fuse(s). The key was in the On position but the engine was not running. I just bought the car in July and it only had 45000 miles on it and looked immaculate.

I checked the DIC error codes but there were no HVAC codes and the codes that were there were all historical(H). I'm not sure what to do next and I don't want to just start taking things apart.​

 

[Junkman2008]

Before we start on any of your questions, answer me this. Have you done an evacuation and recovery of your R-134a?

 

[JamesB]

98 Corvette Bad Driver side HVAC Actuator

Before we start on any of your questions, answer me this. Have you done an evacuation and recovery of your R-134a?

Thanks for the quick response.
I'm not sure what that entails but no I have not. I bought the car in July and the air conditioning and heat worked fine when the weather was warmer. I only noticed the no air flow out of the driver's side in the last 2 months or so when it started to fog up and the more rainy and cold the worse it was. I quit driving it as I was driving blind at times.

JamesB

 

[Junkman2008]

If you do not know what that is, you have definitely been reading all the WRONG threads. You have a TON of people posting on this issue who have never had to deal with it, a TON who have dealt with it completely wrong and a TON who are just repeating what they've read and heard. I have advised folks to do this in THIS thread and a bunch of others. If you trouble-shoot this problem wrong, you're going to end up spending a BUNCH of money and wasting time replacing all the wrong parts.

STEP 1: Do a evacuation and recovery of your R-134a so that you will know the EXACT amount of refrigerant that your AC system has. Why is this the MOST IMPORTANT STEP? Because LOW REFRIGERANT is the NUMBER ONE CAUSE of the problem that you are experiencing on a C5 Corvette as old as yours. END OF STORY. The process is not cheap ($50 - $120), but is the best money that you will spend in diagnosing this issue.

Your car is 17-18 years OLD. The AC system is a sealed system and should NEVER leak. On a C5 as old as yours, leaking refrigerant is a COMMON problem. If your refrigerant level drops low enough, the AC system in the car is DESIGNED to not operate the AC properly in order to do TWO things. One, avoid burning up the AC compressor and two, notify YOU that there is a problem with your AC system. An evacuation and recovery of your AC system MEASURES the amount of R-134a in your AC system. It is usually performed with a machine like the Robinair ACR2000 R-134A Recovery Recycling Unit. Once your R-134a has been evacuated from your system, the person performing the process will immediately be able to tell you if your refrigerant is low or not. If it is low, YOU HAVE A LEAK that must be addressed. They will then recharge your system and pressure test it to see if the leak is too bad to leave the system charged. If not, they will leaved the proper amount of R-134a in the system and you will have cold air until the system leaks enough refrigerant back out and the level becomes too low. Once that happens, you will be sitting right back where you are right now.

Some Corvettes use one amount of refrigerate and another year Corvette may use a different amount. They are NOT all the same. Using too much refrigerant is just as bad as having too little. Your car uses an EXACT amount. This is why I have my car's service manual, the same one the dealerships use.

So now you know the FIRST thing that you need to do. Doing anything else first is not only the WRONG way to address this problem, it's down right stupid if you understand how the AC system on this car works. A LOT of people don't. I educated myself first by reading the service manual and then bumping what I leaned off guys like Evil Twin from CF (one of the engineers who helped design this car from the ground up), and Paul Koerner (C4C5 Specialist - the E.F. Hutton of Corvette repair). Until you do that evac and recovery, you don't do anything else. The results of THAT test will determine your next step.