tnmotown

iTrader: (107)

Well I've noticed that when I go WOT, the battery gauge will drop down touching the red zone and trigger the "Check Gagues" light on the cluster. Then once I let off the throttle and coast around, my gauge will back up to around normal and the light will turn off.

Could it be a bad alternator by chance? I bought a cheapy one from ebay a few months ago. What about a bad ground? The alternator connector has been cut before by the previous owner, so maybe a bad connection there.

Also, in relation to my voltage drop, my car idles around 700rpms and sometimes it will drop down to 500ish causing the voltage to drop in the red zone.

Any ideas on what could be causing this? Thanks in advance

Majestic9C1

iTrader: (19)

most likely your alternator cant handle the power... alot of guys have their alternators **** the bed when they go WOT...

a good solution is to get the Silverado Alternator with 145 amps


why GM decided to stick a 102 amp alternator on an LS1 is beyond me


edit: just noticed that the exciter wire was cut before.. how is it connected?? is it soldered and heat shrunk?

tnmotown

iTrader: (107)

That exciter wire was cut and put back together with a crimp piece, it's not soldered. So I'll have to double check that.

Is their a part number for that silverado alternator? And it's a direct fit?

Majestic9C1

iTrader: (19)

any 145A alternator from a Silverado or Escalade up to 2006 will work..

you have to get rid of the LS1 alt bracket though..

BubaGumpShrimp

iTrader: (1)

to me it sounds like the alt is about to go. I just had this issue with my new alternator i put in, in jan... The alt would work ok when at idle but once it started to heat up or you bring the rpm up the voltage would drop off. From what i understand is that the diodes or one of the diodes is overheating/leaking and causing it to not charge.. I replaced it with a new one (lifetime warranty) and works fine now.... One word of caution, if you keep wasting alternators, check to see that your power steering lines are good and not leaking. Mine was and i had gone threw 2 alternators before i noticed the power steering line was leaking right into the alternator..

rjla67

I just went through the same issue (see my thread on what I went though). Turns out the brand new AC Delco from GM is a rebuilt unit, and I smoked 2 of them right out of the box so I'd stay away from them. I also smoked an Advanced Auto one since they too are the same 102amp alts.

I finally talked to a GM tech and the only ones that are rebuilt and will handle the load believe it or not is Pep Boys for they use bigger diodes to handle the load. I'm running that now with no issues but if/when it happens again I will have it rebuilt locally to my needs and stop replacing them at a parts store for they all but that one have the same issue.

The other option is just to get the 145amp truck one as well.

rjla67

Quick question: if one gets the 145a version and removes the alt bracket how does the idler pulley work then?

BubaGumpShrimp

iTrader: (1)

i have the truck one, mine was for a hummer and got it at advance auto... The bracket you remove is the one on the back of the alternator. You then only use the 2 front bolts and bracket with the pulley.

rjla67

Gotcha. That makes sense. This is good info.

BubaGumpShrimp

iTrader: (1)

word of caution,, the truck one is bigger and a bit harder to get into place, i suggest taking the bracket out with the alternator, your belt will be a bit short too so you may need a longer one as the truck alt case is bigger and moves the pulley further away.

Footlead

iTrader: (18)

I put one off a truck on mine and no issues and works great. The rectifier is bigger and spreads the diodes out farther apart than the LS1 factory version. great mod---I bought mine from Pickurpart used and its been working great for couple of years.