silversrtman

iTrader: (20)

Alright i started noticing at night time my lights would dim when I would go wide open throttle. So figuring it was my AC Delco reman alternator I installed last year, I contacted the company I bought it from and they warrantied it. They sent me another reman and I installed it...same thing...So i figured hey thats weird but maybe 2 bad remans in a row, so I then requested a brand new alternator. They sent me one which I just installed and I am still having the same problem. I also have a brand new battery, and my buddy whos a mechanic tested my grounds with a multimeter and they tested out ok. So I am at a loss....anyone else with this problem or something similar? Any suggestions, comments, or anything else is extremely welcome. Thanks.

sjsingle1

iTrader: (1)

why else would the volts drop...if not the alt?.............the alt just cant keep up........try a truck alt or bigger

95maroz28

iTrader: (21)

I've been having this problem lately at high rpm but im hoping the belts just slipping since theres no tension left from the belt stretching. i have the alt relocated tho.

Gray86hatch

iTrader: (83)

belt slip.

mine started doing it his weekend. I have to tighten it up. only dose it above 6800

Tim

silversrtman

iTrader: (20)

Well at this point I am assuming its not the alternator since I am on alternator #3 trying to fix this problem. Three bad alternators in a row is possible, but highly highly unlikely.

lol 6800? Wow....I hope its just belt slip mine does it after 4k at 50%+ throttle.

SWEET98SS

iTrader: (8)

Jow is your exciter wire? The little tiny wire that connects to the alternator.

silversrtman

iTrader: (20)

thats in good shape, never broke it or anything.

oldmano2z

it is your alternator. the diodes in it a too small to accept the inrush of voltage. there is a writeup this subject called:my constant alternator woes or something like that. i'ts here in ls1 tech, maybe a sticky it explains it completely. truck alternator 145amp type will cure it i did mine a new one. bone yards have them also as an option. over rev frys diodes.. great article i wish you good luck and hope this helps. the oldman..

sjsingle1

iTrader: (1)

https://ls1tech.com/forums/generatio...-failures.html

silversrtman

iTrader: (20)

Thanks guys I will check this out.

00pooterSS

iTrader: (40)

That doesn't mean the contacts are good. Those connectors go bad. Get a new one just for good measure AC Delco PT1136.

That is my thread about the alternator failures. I've seen it all I think.

It sounds like belt slip, but our cars normally throw belts when they slip, mine did. I put on a high wall tensioner pulley and it stopped the belt slip and the belt jump. It put a hair more tension on the belt.

Try this, it's cheap. https://ls1tech.com/forums/generatio...swap-pics.html

Can you hold the revs while parked and see the voltage drop? If so hold ratchet on the tensioner bolt while someone revs the engine, apply more tension to the belt while revving it and see if the voltage comes up, if so the belt is slipping, if not your alternator is dropping voltage.

cookba

iTrader: (10)

is there a schematic or pics that show the exact routing of that exciter wire? I might get a new one and run it and leave the stock one alone stuck out of the way since its all wrapped up with other wires in a wire loom.

silversrtman

iTrader: (20)

Thanks man I think im going to have to try that. As for the connector it looked fine when I had it off, and the car only has 50k and from the looks of it underneath, was garaged for its whole life. It also seems like belt slip to me, the only thing is the belt looks fine...But before I buy a new tensioner I might as well try that buick pulley.

00pooterSS

iTrader: (40)

You can't LOOK at the connetor and tell if it is making a good connection, and the belt looking fine won't have much to do with belt slip. The belt slip is usually caused by a weak tensioner. The belt also stretches over time and will cause it to be under less tension as well.

All the parts are old, it doesn't matter that they only have 50k miles when they are 10 years old man.

It would be a good ideal to do a new belt and tensioner along with the connector. I also like the buick pulley if you are revving the engine high, it helps keep the belt on.

MbT

What was the solution, i am facing the same issue

01ssreda4

iTrader: (96)

Since you drug this old *** thread up.....

You sir are an idiot. An fbody doesnt require a "truck alternator", even one with EXTRA electrical demands much less a stock vehicle. Giving poor advice and spewing false information just makes people dumber.

nine8ss

iTrader: (5)

Wow, did someone **** in your cereal this morning?

I had the same problem and the truck alternator fixed it.

Not required, but it works.

01ssreda4

iTrader: (96)

Thats funny, cause I've run a stock fbody alternator for no less then 11 years and at times with more electrical demand then stock with zero issues. Having someone throw a bigger alternator at the problem isnt the correct answer. Sounds like he has a clear ISSUE with the car, charging system, and associating wiring/cables. I would fix that first! Properly diagnose the car first. 99.99% of cars do not need bigger alternators.

G Atsma

00pooterSS went thru his vehicle with a fine tooth comb and found nothing wrong anywhere. But he kept going thru alternators until he put in a used 145 amp truck unit. Now maybe he didn't need the 145 amps, but there is something different about the truck unit that keeps it alive where the OEM units dies every time. And being a long-time tech, he should know what he's talking about. You have a point; no one needs the 145 amps, but there is another aspect about those alternators that is tougher than the OEM units

SLP IROC-Z

iTrader: (14)

My exs car did that ended up being the DRL module