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this non working AC is killing me!!! HELP!!!!! PLEASE HELP!!!

Discussion in 'The Garage' started by Pookster, Jun 13, 2004.

  1. Pookster

    Pookster 1/2 ton status

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    This is a little long, but I wanted to give as much detail as possible.

    This is on my 92 pickup, which GM decided to use "electronic" controls for the HVAC system. When I got the truck, It wasnt working right- P/O said it might need a recharge. But when I checked the pressure, there was plenty of freon inside!

    So then I was clueless, cause the display would would blink AC- something was causing the relay not to work right-

    When I took apart the dash, i noticed that the old control display box had some signs of burnt circuit-, so I cleaned it up, added some fresh solder, some dielectric grease... and voila it worked-. FOR A LITTLE WHILE!

    It only works for about 10-15 minutes and then dies! It seems to work just fine at idle- Just after you drive it for a while, it just stopps working! Once it stopps working, there was only two ways to reset it- unplug the box, and plug it back in, or disconnect the battery.

    This seemed rather odd- in addition to that, I was getting an extreme voltage drop recently whenever I tried to use the Fan or Ac- the whole dash would dim, the gauges would read funny. Feeling that the box was the issue, I replaced the control box.

    I put in a new control box, and let the truck idle for 30 minutes- the AC worked flawlessly-. However, driving it on the highway, the same "flashing AC" came back up. No voltage drop issues however.

    What could this be? Is there some sorta relay elsewhere that isnt releasing or getting stuck? HELP!!!!!!
     
  2. 1-ton

    1-ton 1/2 ton status Premium Member

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    I think that the problem is the electronic HVAC control panel. Back in 1993, I bought a brand new Chevrolet 1-ton 4x4 that had the electronic HVAC control panel, and it was replaced three times under warranty. I talked to a couple of GM dealership mechanics that said the electronic HVAC control panel was a piece of junk that was constantly burning out on all GM vehicles that had one, and that there was nothing they could do to stop them from burning out, but replace them under warranty until the truck was out of warranty. If you want to go to the trouble, you could change it to an old style manual cable and switch system.
     
  3. Pookster

    Pookster 1/2 ton status

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    Acutally, it doesnt fully burn out. I was almost tempted to bypass the unit (since all fan and diverters still work) and just jump the Pressure switch.
     
  4. afroman006

    afroman006 1/2 ton status

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    Um, would my 91 burban happen to have this electronic HVAC? I'm having all kinds of A/C problems with it and cant figure it out... /forums/images/graemlins/angryfire.gif
     
  5. Pookster

    Pookster 1/2 ton status

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    ok, cleaning out the contacts did not help for very long. Same issue.

    Is it wrong for me to make an in cab Pressure jumper switch? this would force the AC clutch to engage, and then I would have AC.
     

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