electrical problem

[broke_okie]

I have a 1971 F100 4x4 with a 390 FE engine. It has the stock alternator and voltage regulator. When the engine is not running my battery has 12.69 volts but when I start the engine and it is running it shows 11.67 volts. I had the alternator tested at the auto parts store and they said it tested good. I replaced the voltage regulator. Does anyone have any clues. Oh and the alternator is getting too hot to touch after running only 2 minutes. I think the alternator is bad does anyone have some input?Thanks ....stumped.

[gonzalo medina]

I would check all the grounds in the charging system. Do you have any extra electrical accessaries hooked up to the truck?

[ima71 trucks are older]

I had the same problem and it finally fried the charging harness.
The bad harness had a short and would overheat the alt, melting the insulation in the windings. this would also kill the regulator.

No charging, replace the alt and it kills the regulator. replace the regulator and the alternator fries.

This is the diagram for building a new charging harness.
http://www.fordification.com/forum/view ... hp?t=23310

[broke_okie]

I replaced the alternator and voltage regulator...the alternator was fried. Thanks all.