1990 Chevy Silverado V8 Four Wheel Drive Automatic 175000 miles
Alternator not charging. Changed alternator with no change. A+ wire to alternator reads 12.5V with key off. After starting engine, voltage went down to 6V. When I jumper a wire from battery to alt. It works fine. Question where does the red wire from the Alt. A+ terminal go? The tilt steering column was just removed to tighten the 3 bolts that work loose after time. Could this problem be related to that work? I see a purple wire on starter sol. And no red wires on terminal strip on firewall. I am afraid this red wire is loose or has a bad connections somewhere but can't find where it goes. A schematic would be helpful.
I just turned on the key and got the Bat. Warning light with the Volt meter showing about 10 v. When I started the engine the Lt. Went out and it started charging normally. Tried the same thing again with the same results, so now it is intermittent. Thanks for the schematic. Now I think I can trace things out and maybe find the problem.
When I put the cover back on the junction block at the back of the engine bay, (which loads the wires a little) the alternator would not come on line again. Also voltage at the battery was about 12.5 and at the alt. Terminal was 10.7. Thinking I might have a fuseable link that was causing high resistance, I disconnected the battery neg, and was going to check the wire to the alternator for resistance. When I put a socket on the nut it took no resistance to turn it. Turned out someone had once hooked up another lug and wire with fuse holder for a trailer brake or something to the same terminal and had evidently left it slightly loose. All of the other nuts were tight. I cleaned the connections, put a star washer under the nut and tightened it down, reinstalled the cover and it works fine now. Thanks for the wire diagram with color codes.
have the same problem?
Saturday, February 27th, 2010 AT 1:03 PM