A friend of mine has a 96 1 ton, the engine is stock, 697,000 miles. The tach is pegging out at idle, the alt will sometimes show complete discharge and the lights will flash. The Dodge house said they thought it was the computor, (the one behind the air filter) it was replaced, now the lights don't flash but the tach still pegs out and the alt. works off and on. I think it is a ground, how many are there and where are they all located. Anyone got a chart or would know what else might cause this problem. 
