Hi all - back again with this week's dumb question, but auto electrics continue to mystify me. Symptom - red AMP light burning bright except for occasional spurts on off-ness. Does not go on when cranking but comes on immediately when engine catches and stays on. Voltage checks seem OK, battery not losing power, fan belt not loose. Problem appeared after header installed; that's the only thing different. No wires were changed during that event. Where to start looking for the short? TIA, David

I haven't taken advantage of Ron's re-worked fuse blocks, but have dissembled, cleaned and reassembled three of 'em. The get pretty cruddy. In all three cases, re-conditioning the box cleared up the problem you describe. His are better, since he tins them and all, but I couldn't be without the boxes for the few days they'd have to be gone. If you have time, his would probably be worth the wait and the few bucks it would cost.

Jim Hampton

David;

Refer also to a 122 wiring diagram: http://www.intelab.com/swem/122S%20Wiring%20Diagram.jpg

The fact that this problem started after you installed a header, may just be coincedental...and the AMP light going off during cranking is normal.

The AMP light monitors the charging system by lighting when it senses a difference in voltage between the battery (by way of IGN switch and Fuse1), and generator output.

Additional info at: http://www.intelab.com/swem/service%20notes.htm#Electrical%20Equipment

So...if there's no Gen output and IGN is ON, OR there is Gen output and no Battery voltage, you'll see it lit.

IF your charging system is OK, an open Fuse1 (or associated connections) can also cause the AMP to come on...try spinning the fuse in its holder, as a quick test...if this causes the AMP light to go out, your in luck, but its definately time for some anti-corrosion work and then prevention...time to read: http://www.intelab.com/swem/gastight.htm

Good Luck

Ron [and Jim] - thanks for the tips; hopefully this will lead me to a solution. Another suggestion is possibly that the regulator got fried when the boys were welding the header. David

David;

That's not unheard of, but pretty unlikely...you would have to set up some pretty specific conditions in terms of (unintended) current paths to zorch things in a car...and most welders know (or are supposed to know) to hook the grounding clamp right where they are intending to work, so that the welding current is passed strictly through the weld area, and does not take a round-about path through the rest of vehicle.

Cheers