rja614

I own a 1990 convertible with only 26k miles on it. Last weekend I went for a short ride and everything was working fine. However, on the return trip I noticed that the display on the Climate Control was lit but blank. I then found that the AC and Heater controls weren't working. In addition, the radio turned on, but the antennae didn't move to the up position. And there was no sound... I checked the fuses on the inside fuse box on the passenger side, but they were all good.... any help would be appreciated.... Thanks.

BEZ71

having the same problem on my '95 and i ca't seem to get a answer.

ckd

It's definately the fuse. I have a 90 that had the same problem to the "T". The speakers antenna and ac/heat are on the same circuit. A new fuse solved all my problems.

BlackPearl1

rja614, did you ever figure out your issue? I'm having the exact same issue with my 1990. I installed some sound deadening material today in the read hatch area, and to keep the battery from dying while the rear hatch was open all day (didn't want the left/right side courtesy lights to stay on all day), I pulled fuse #1 which controls courtesy lights, antenna, Bose speakers, and AC. The doors were open for quite a while as well as the rear hatch window. When the project was finished I put everything back together and re-inserted the fuse, and saw the courtesy lights come back on and so thought all was good.

Took the car for a test drive and noticed the heater/AC control panel was lit up but there was no display and the controls were not responding. Nothing was working. Windows fogged up real good during the test drive.

I pulled fuse #1 again and checked it and it tested good. Tested several other fuses as well that showed AC in the description in the manual (such as fuse #2, fuse #3, fuse #7, fuse #11 (description was dome lights and CCM), fuse #12.

Does anyone have any idea what could be the issue. I read on another forum that a loose wire /connector on the driver's side kick plate cold be an issue, so I will check that tomorrow, but I'm not hopeful that's the issue since that area was not disturbed during my project and so not sure how anything could have become loose in that area.

Welcoming any help. Thanks in advance.

BlackPearl1.

CorvetteRules

He was last on the forum November 2005.

BlackPearl1

Yeah - I was thinking that but was hoping someone else might see who may have some helpful ideas.

puterami

I've been doing some research for my 96. This thread *may* help you.
https://www.corvetteforum.com/forums...t-working.html

BlackPearl1

Puterami, Thanks for the link. I actually had already found that link and read through it. I was hoping to find some easier troubleshooting tips before I jumped into pulling out the HVAC programmer. From the experiences of others, that can save you money but sounded like it was a b***h to get out and then you had to have some soldering skills. I CAN solder, but not much experience with circuit cards (mainly soldering plumbing, etc.) but I'm handy so could probably figure it out.

But it seems I may be one of the few who are getting off lucky in my situation. This morning I ventured out to start troubleshooting and started with checking fuses. I was planning to go through every fuse and also check to make sure power was getting to the input side of each fuse socket. I only had to check the first fuse (#1 in my block). I had checked the fuse last night and it was good, and it tested good again this morning. But I measured the voltage across the open fuse socket without the fuse plugged in. I expected the voltage across the socket to be 12 volts since 12v would be on the input side (I assumed) and 0v on the output side with no power feeding through. I did measure 12v initially, but then as I checked and rechecked it again and again, the voltage across the gap went to near zero (can't really explain this). I double-checked a few times just to make sure I was getting good contact inside the fuse socket on the terminals, and kept getting only about .5 volts, etc. Again I couldn't explain why I got 12v initially but now was not getting the same reading. But in either case, I figured I'd reinsert the fuse and see if anything had changed as far as getting a display on the climate control head. (One thing I noticed as I inserted the fuse was a small (very small) spark as the fuse went in. Not sure if that's important to the story). But on inserting the fuse and starting the car, the climate control once again had a good display! You can't imagine my glee LOL. I was all down in the dumps last night after a long day of adding sound deadener and trying to make the car better than it was, only to take a big step backward with a difficult to fix problem. I shut off and restarted again just to make sure it wasn't a fluke, and still got a good reading so I will assume that I'm good to go for now.

I did order a set of used Factory Service Manuals (main manual and auxiliary manual for electronics) for $77 on ebay, so I'll have that for next time when I have a problem. But at least thbis time I feel like I solved the issue with something kin to "turning a computer off and on again to fix an issue", mine was about as easy as that it seems.

Thanks for the link and maybe someday (but hope not) I may need to go through all that. Hopefully not for a long time.

Dennis (BlackPearl1)

Cooter77

Same thing happened to mine. All I had was the lil' light on the control panel. ****Fixed now**** May not be your fix but this is what fixed mine. 1990 c4 fuse box pass side end cap of dash. Top row, #1 fuse was blown. (Unless you bend down you may miss the top row like I did). Replaced fuse, blew again. Took the 2 screws from the rear of the shifter panel off and the one screw in the cup holder and pulled up the cover. (Note, already had the front plate off that surrounds the ac/heater control unit off) What I found was all kinds of coins, seat cover metal clips and chewing gum wrappers...everything I ever stuck in the cup holders or maybe the center console that slide through and shorted out the cigar lighter. Still have problem #2 blower stays on and I have to pull the connector to shut off. I have 8 cars and trucks on the road and really don't want to spend too much more. (spent $200 to get the control unit repaired which I probably didn't need...old one was doing same thing) Ordered a $40 blower module that fits a 93 jeep cherokee with auto temp control instead of ordering another $200 corvette part. If that doesn't fix my blower problem...going to run a toggle switch into the inside (with an in-line fuse) so I can shut it off when not needed. Hope this helps. I'll let you all know about the $40 blower part once it arrives. Bad side....If it doesn't work and I toggle switch it, may be on high all the time. ken (Cooter77)