Question about 1990 Chevrolet K1500
Problem is in the a/c circuit. Any time the defrost is on the a/c compressor will cycle on & off as it is used to dehumidify the air directed to the windshield. That's why the fuse can blow even in defrost mode.
Unplug the power connector at the a/c compressor and see if the fuse still blows. If not, then with a dmm or vom test a/c clutch winding for short. If ok, then test clutch diode for short. The diode is usually mounted at the clutch winding, but I've seen Chevy's with a diode that plugs into fuse/relay block under the hood. I have replaced these so don't overlook it.
If fuse blows with compressor unplugged then first check circuit between compressor and a/c relay (power side) for a short. It's possible for the wire to rub a bare spot in the insulation along it's travel along the block, bracket or manifold to the compressor. If ok, then test from relay (winding side) back to switch.
Posted on Jun 24, 2009
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
Tips for a great answer:
Sep 12, 2014 | 1997 Chevrolet Blazer
Jan 12, 2010 | 1992 Chevrolet Cavalier
Dec 31, 2009 | 2004 Ford Focus
Aug 01, 2009 | 2000 Ford Ranger SuperCab
Jun 24, 2009 | 1997 GMC Safari
Aug 31, 2008 | 2001 Lincoln LS
396 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: