So.... Anyone have any idea why it takes 10 minutes for my ALT light to go out after I start my Runner up in the morning???

A little history first. I replaced my alternator recently with a HO one from DC Power. I verified with Dave (@ DC Power) that the alternator is working properly (he's been great to deal with btw). So there is something else going on with my charging system.

What happens is this... I get in the rig in the morning, start the thing up and the "ALT" light stays on and there is NO output coming out of the alternator. After 10 minutes (like clockwork) all of a sudden the light goes out and it's charging. Every morning it's exactly the same too. Continuity on the 100 amp fuseable link is good. The 7.5 amp fuse in the cab is good and so is the one under the hood.

Incidentally, I cut the "ALT" wire (yellow) and checked the output voltage and there isn't any.

Seems so odd that once it's warmed up it's fine but it's just in the morning after it's been sitting overnight that I have an issue.

So... any ideas???

 

Belt slipping?

 

Nope, belt is tight.

 

Have you had the alt tested at like autozone?

Id assume its something internal in the alt. I mean you either rebuild it or get a new one. But it works. But will it fail and screw you over?

Wierd one for sure.

 

It's not the alternator. It's a problem with the alternator circuit somewhere. If I bypass the circuit, the alternator charges night away.

 

Then Im stumped. Have no idea what the 10 minutes is about.

 

No kidding! Thanks for tryin' though.

 

Anyone else???