Corso

I have a 1994 LT1 and the climate control locks up after about 15 seconds. Before it locks up the buttons work and I can hear what I believe is the changing of the vacuum from under the dash right above the throttle pedal. I then hear what sounds like a motor hum and that's when it locks up. It will only blow air out of the floor vents regards of what LED is lit on the control panel. Anyone have or know of this problem?

Cliff Harris

Can you see the diagnostic codes from the system?

How to get the codes and what they mean:

http://forums.corvetteforum.com/1585305121-post2.html

Corso

Yes, I've seen the video and it passes with a -00. I took out the head unit and cleaned the all contacts looked for cold solder breaks and even put the diodes, transistors and caps on a Huntron. All test good. I'm trying to take out the C68 Programmer but have no clue to how get the push nut off the housing for the vacuum tubes. There's not a lot of room under there. A friend of mine says it sounds like a vacuum leak. But the timing of it locking up seems like it's electronic. I've also read your thread about the 140 ohm resistors but this Programmer is different from the pictures you posted.

Corso

Well now to beat the band...the starter won't engage when I put everything back together. This has gone from bad to worse. I have everything back apart. A/C control out, radio out and I haven't a clue as to what I did to make this not start. This used to be my dream car. Now... more like a nightmare.

rochhound

sounds like the vat security system.
its in the area your working on theres a wire that goes from vat system to the key it has to read the write resistance for the security system to allow the starter to turn over.
there a lot of good reads the vat security system do a search
good luck steve

Corso

The security light is on when turned to the run position. I'm replaying what I did and I think I might have f'ed up. I used the blank key that was in the console when starting it after I had put it back together. I read in the owner's manual that if the PASS key is not used it will time out for 3 minutes. Is it possible to confuse the VAT if the blank is used several times? Because everything else looks good as far as wiring goes.

Cliff Harris

The -00 is just the beginning of a whole series of menus. You need to go through the whole process.

Cliff Harris

If you can start your car with a blank key then the VATS system has been bypassed.

pcolt94

Read this link I wrote as it pertains to the 94. See if the symptoms I described pertain to you. If they do, there is a lot of information on how to repair it.

https://www.corvetteforum.com/forums...-repaired.html

Just to tell you up front here, the lock nut and vacuum hoses do not have to be removed.

Corso

On -01 when I hit the fan button it gives a code of 75. Okay, I think I know how to read the codes. 75 is the temp setting. The ones that I've gone trough seem okay. The problem is it locks up before I can get to all of them.

Corso

Cliff I should have been more specific, I 'tried' to start it with the blank key. It never would start using it. But after it sitting overnight it starts every time with the PASS key.

Corso

Great thread. Nice to know about the cap.

Corso

My 94 is back up and running with cold air. Thanks Cliff, pcolt94 and rochound for you help and replies. It was the 33 mic cap that cause the lock up. PITA but saved me $ and that is always a good thing.