I've thought that too possibly, I'm gonna check it this weekend when I have a while to diagnose it. If it's not slip, then it about has to be the alternator...

I'll let you guys know what I figure out later this week, if I don't get any time tonight.

 

If I just let the engine free rev (rev in park/neutral), it doesn't happen at all, is this pointing to belt slip?

 

not necessarily...the belt is still spinning when in park/neutral....

but it does sound like it would be the alternator on it's way out....because under WOT it should *in theory* actually start charging the battery more so if anything the volts should jump up rather than die down

 

mines been doing it for a while to. Even have a new alternator cuz mine when out over the summer. Still does it. I may have to look into a new belt or something some time to see if it fixes the problem. Makes sense that is slippage cuz after a few seconds the voltage pics back up.

 

Kinda what I thought, I don't think it's the springs/brushes in the alternator because just reving it in the shop it doesn't happen. When I went with my 200amp alternator, I went through 3 or 4 belts trying to find one that would fit and still put some decent pressure on the tentioner, I'm gonna check how much pressure is on that pully or how much belt play I have when the high isn't 6 degrees.

Josh, if I get it done I'll post up what I find.

 

come to think about it. It may have done it after I replaced the original alt with a new one. I have a couple stock alts out here I could try.
Maybe there is a discrepancy between the factory alt and a new/reman

 

I realize that

If I remember correctly, the alternator has done it since it was new, belt is the next cheapest thing to check though, so that's where I'm going to focus on next. lol

 

I've still got my stock alt... it's not out out yet, just has a bearing going out of it.

 

And I believe the answer is .......... Belt slip..

When working on it I got under the hood and ran the throttle by hand, when you give it a quick shot of throttle, you can watch the belt walk on the idler pully. Looks like I"m gonna be looking for a slightly shorter belt, or a much tighter tenstioner pully

 

Having same problem. Going to swap my new 145amp with Oem Denali alt. Hope it works cause wot above 120 my hids start flashing like I'm a cop and losing fuel pressure.