A/C Issue

[BakInBlak]

Having an issue thats perplexing me.........:W

My '89's A/C Panel lights are off most of the time like perhaps the fuse is blown or something, yet the A/C itself works fine, then while i'm cruising down the road it'll light up the way it should w/the digital temp screen showing #'s and everything. I've gone thru all of the fuses and they're just fine. What could be causing this? Can anyone shine a little light on this? Thanks.

 

[Moonunit 451]

Welcome to It's most likely a ground (wiring) problem somewhere. Could be in the dash itself from what I've seen.

 

[Baldie88]

I had a similar problem with my 88. I found the contacts in the unit were corroded. You can take the unit out and take it apart and clean them. However after doing this a few times I just got fed up and bought a new HVAC unit. They aren't cheap however but I got tired of pulling the unit out every couple of weeks.

Hope this helps.

Ron
"Baldie88"

 

[BakInBlak]

Update

Well i went in and checked what Baldie suggested, but the contacts look almost new. I adjusted the back plug making sure it was tight and the unit still has no lights. This thing is diving me nuts! :W

 

[Baldie88]

I should have made my self clearer. The contacts are within the unit itself, not the plug in contacts at the rear of the unit. If you look at the unit once you have it out there are two tangs on the sides of the unit (if I remember correctly). Be careful and pry these tangs so that the unit itself comes apart (broke one on my old unit). The front of the unit slide out of the enclosure. Once apart you'll see the circuit board inside and those are the contacts that were the problem on mine. I cleaned them with just an eraser on a pencil.

Like I said this worked for a while but I eventually had to replace the unit. You could try a search on "hvac" or C68 (I think that's the RPO code) and see what you come up with. I'm tied up at work or I'd look for you. I just didn't want to give you bad information. I know there are procedures I've run across before on how to fix this problem but all my info. is in boxes since I'm in the process of moving.

Good Luck.

Ron
"Baldie88"

 

[BakInBlak]

Y'know, it was me who didn't clarify actually (oops!). I did take it apart when i had it out and those contacts were fine too.

 

[Baldie88]

I guess we're both a little misunderstood.

I eventually bit the bullet and bought a new one from I think Corvette Central. If I remember correctly it was about $250 plus the core. That's about your only option if cleaning the contacts didn't work

Baldie88

 

[BakInBlak]

New update

Well, I just took a nice long drive to an old friend's house today (158 Mi. roundtrip) in the new toy and found another clue to my A/C dilemma. It appears when I have the lack of panel lights on the A/C control my courtesy light on my rearview mirror (the small one that illuminates the general cupholder area) doesn't work either, but when the A/C panel is working, it does........?????
:J

 

[Baldie88]

Well I hope someone else with more knowledge will jump in because I don't have a clue as to what the problem might be.

Ron
"Baldie88"

P.S. Your new avatar made me throw up!!:L

 

[Jeb]

Maybe this will help.