Two Problems

[Kalgorn]

I came home this weekend so my dad and I could see if we can fix my AC. So far... it's not fixed but the problem seems to have been found. I've got a Haynes book on it but the book really isn't very good. It focuses more on Grand Prix, Cutlasses, etc. I don't think there is a schematic for a Lumina. It has some for a Cutlass so I just used those.

 

Problem 1: AC doesn't work. The compressor does not initialize due to the clutch not initializing. Why? Using the schematics in the book it's been decided that the clutch is not initializing due to low refrigerant. We made sure the clutch can spin like it should but hooking it up directly to the battery. That works fine but the air didn't get cold either... another clue to the low refrigerant theory.

 

Problem 2: Air control system doesn't work. By that I mean the buttons in the dash to control the air flow in the car. Off turns the air flow off but none of the other buttons do anything but turn the air flow on. I think it's stuck on blend. I'm not sure what to do to fix this. I'm pretty sure there's a damper behind the dash that changes the air flow depending on what button you push, but I haven't gotten into there yet. I'd rather not have to so I'm looking for other ideas first. I also think it could be a vacuum line. There doesn't seem to be a vacuum line schematic in the Haynes book for my car so that doesn't help either.

 

What do you think? Any ideas?

[DiscoStudd]

Remove your control unit and crack it open. Look for the main IC chip (it's looks kinda like a "spider", it's rectangular with several "feet" on each side.) Flip the circuit board over and take a soldering iron to each of the terminals of the IC chip. What happens is the small wires inside the chip break away from the outer terminals and when you apply a little heat to each terminal with a soldering iron, they melt back together.

 

The control unit on my old 92 LeSabre was giving me fits just like you describe. I have a friend who has experience in the electronics field who told me to try the soldering iron trick. I did exactly as he told me, and that fixed the problem. The problem came back about a year later, so I removed all the solder from the IC terminals' connection to the board and resoldered them all with fresh solder. Well that worked and the unit was functioning perfectly until I traded the car a year and a half later...