1988 Chevy pickup electrical problems

I seem to be having some strange electrical problems on an 88 Chevy Silverado pickup. The most troublesome one being the heater/AC control unit. It flickers and turns on and off, and is not working much at all
now. The power locks stopped working and the wipers sometimes will not shut off. I thought maybe the heater/AC control unit was gone, so I got a rebuilt unit and put it in. Same problem, it flickers, and turns on and off, etc. Has anybody had this problem? or have any idea what could be causing it?
thanks, - Paul
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If it's the same problem I had with my 92 then its a bad connector. I actually had smoke but didn't catch fire. Amazing that the fuse did not blow. Anyway the connector I am talking about is behind the heater control unit. Pull out the heater control and follow the wiring harness into the dash, Its been a while but I believe the connector is gray or white, a six pin Molex connector. Pull it apart and see if it is burnt to a crisp. If I remember correctly the ground and pwr pins are right next to each other. When I was working on mine I let the control hang and went moving wires and I could make the unit turn on and off. Good Luck JRE
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Behind the glove box, next to the blower should be the power connector MasterMech is talking about. They usually melt when the pins loose their spring. A RatShack Molex connector is a good replacement for it.
As for the others, they may not be related. Did they all act up at once?
Cheer

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check ground to frame. your ground goes to engine but you also need one to frame. almost garrentee that is your problem. 10ga wire at least.

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I checked all the connectors behind the glove box. They all looked clean with no evidence of any shorts. Are you saying to just run a grounding wire from the battery to somewhere on the frame? Have you seen this cause this type of problem before? Is there a way to check if there is a ground to frame problem with a voltmeter?
thanks, - Paul
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Yes, you can check it with a meter. There should be a braided ground strap somewhere from the engine block to frame, mine is on the passengers side. you should check to make sure its there.
Cheers

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The connector I am talking about is definitely behind the heater control unit and not the glove box. At least it is on my 92.
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There should be a wire from the negative terminal to the fender and also a braided cable from the engine block to the firewall These are the ground paths for all circuits that use "Chassis" ground as opposed to an actual ground wire.
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snipped-for-privacy@nokia.com (Paul Girouard) wrote in message

Thanks for the info. I'll pull out the glove box tonight and take a look. The electrical problems didn't happen all at once, so maybe they're not related. The power locks were working, then started working intermittently, then stopped working altogether. - Paul
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