I have a buddy who has a 97 2500 454 and the battery will not stay charged. He has replaced the alternator and the battery. He even took the alternator back and hooked it up to a machine to test it and it passed. If he has someone to jump start the truck it starts right up but once he starts driving the lights dim and the radio shuts off and then the engine dies. We are both stumped by what is happening. Is there something else in the charging system that will not allow the battery to charge?

 

sounds like a massive power draw....how about the starter? have it checked....my money is on the starter.

 

nope starter checked out good. So apparently this all started after he hooked the jumper cables backwards so who knows what the hell is going on. Fuel pump could be staying on or the pcm is fried or some other gremlin.

 

Our 97 Suburban with a 454 was killing batteries for no apparant reason. It also had a very slight drag when starting. I was preparing for a starter install, but cleaned/tightened all the connections first and it has been fine for the last 3 months. The funny thing is that when I was removing them for cleaning none of them looked corroded or felt loose, but the gremlin was removed somehow. Check all your connections.