alternator issue

**boosted z** · 03-28-2009, 05:19 PM

my ls1 keeps eating alternators. i have had 2 diff mechanics check this out one told me that he thought it was in the computer, the other has no idea... what do i do ive spent alot of labor $ and the car still broke..... bout to sell it lol

**JoshieDoom** · 03-29-2009, 12:16 AM

Ever check the aligment of the alternator? Replace the leads?

**BowTied** · 03-29-2009, 04:19 AM

Have you added stereo or other electrical components?

**bigrondownhiller** · 03-29-2009, 12:48 PM

Where the replacements new or reman units?

**boosted z** · 04-08-2009, 06:55 PM

re-manufactured, i have sub wires and an indash screen power wire for subs is disconnected at battery... have had 2 "of the best" mechanics work on it and still something is wrong.

**BowTied** · 04-09-2009, 03:16 AM

U could have gotten 2 that weren't up to snuff.

But most "mechanics" aren't good ET's (electrical techs). If they don't punt voltage and current meters on the alternator and battery they are just spinning their wheels most of the time on a problem like this.

You need to see how much power (not just voltage) it is making and where. Then how much your call is pulling wit different systems on.

**bigrondownhiller** · 04-09-2009, 10:21 AM

Sometimes a bad starter can cause problems. The selenoid keeps pulling current. How old is the battery? A weak battery can kill an alternator.

**AborTivE** · 04-09-2009, 10:33 AM

I had the same problem with mine. The bearing in the original started to whine after the car went for a swim in a flooded ditch so I bought a re-man alternator and it burned up. So I got another, and after one high rev'ing race against my friend's C5 and that one was done. I bought a new (non re-man) one and haven't had a problem since. I got pretty good at taking them out and putting them back in after that fiasco, lol. Do check the leads though. The power wire is the only wire in the plug that goes into the alternator and it is small and there isn't a whole lot of length to it either. My dad and I accidentally pulled it apart the first time we did it.

**shady milkman** · 04-09-2009, 11:48 AM

the stock 105amp alt is way under powered for everything we have on our cars..something like 10 amps are free for use when you have lights, radio and heat/ac on...there was a tsp about it

**01 SS Vert** · 04-09-2009, 06:22 PM

I just spent 15 hours replacing my alternator and the majority of it was on the wiring. The single wire going to the alternator from the PCM (thin gauge wire, red insulation) broke inside the insulation. Unclip the connector in the back of the alternator (can do with the alternator mounted if you have fairly small hand - I recommend you wear long sleaves so you don't cut up your arm). Unclip the connector and get a voltmeter. Check the end of the plug - it will read 0v with the engine off. Turn the key so the accessories are on -it sound now read 10V. If it doesn't read 10V - you found your problem. This also happened to a good friend of mine. If you cut the wire up about a ft from the alternator, check it again...if the wire now reads 10V - the issue is between that point and the connector. If you replace the connector ($17 from rockauto.com), it comes with extra wire!

I just upgraded to a 150 amp Powermaster, and put in a new AC Delco plug, and it's working great.

Good luck. I spent HOURS chasing down the electrical problem. Kinda odd the wire broke, but the insulation didn't. Took some trouble shooting with a voltmeter to figure it out.

**BowTied** · 04-09-2009, 08:00 PM

Originally Posted by 01 SS Vert

I just spent 15 hours replacing my alternator and the majority of it was on the wiring. The single wire going to the alternator from the PCM (thin gauge wire, red insulation) broke inside the insulation. Unclip the connector in the back of the alternator (can do with the alternator mounted if you have fairly small hand - I recommend you wear long sleaves so you don't cut up your arm). Unclip the connector and get a voltmeter. Check the end of the plug - it will read 0v with the engine off. Turn the key so the accessories are on -it sound now read 10V. If it doesn't read 10V - you found your problem. This also happened to a good friend of mine. If you cut the wire up about a ft from the alternator, check it again...if the wire now reads 10V - the issue is between that point and the connector. If you replace the connector ($17 from rockauto.com), it comes with extra wire!

I just upgraded to a 150 amp Powermaster, and put in a new AC Delco plug, and it's working great.

Good luck. I spent HOURS chasing down the electrical problem. Kinda odd the wire broke, but the insulation didn't. Took some trouble shooting with a voltmeter to figure it out.

It is uncommon but happens generally because the insulation can take heat better than the conductor can. Insulation that is much better at shielding heat can help break down a conductor that otherwise might last...not allowing it to dissipate heat.

But I'd think if he is missing his exciter even intermittently it would do some funky things when running! You should see dips at the V gauge and I would think you should get a code! But I have never seen this one???

**01 SS Vert** · 04-12-2009, 05:13 PM

I'm 99% sure mine broke due to tension when removing the old alternator.

**BowTied** · 04-12-2009, 07:35 PM

Very likely. But the aforementioned is why the insulation survives even when the conductor gives up the ghost.

**boosted z** · 04-13-2009, 08:05 PM

i can take the alt back and get a free replacement, but should i try to get the cash back and put it on a higher amp alt, the free one i would get is a freakin reman......my car has the alt on the bottom of the motor bc of the blower so it makes the wiring even worse.

**BowTied** · 04-14-2009, 03:32 AM

Often times getting cash back is a problem. Not to mention so many alternators out there are reman. Play on the heart strings and your alt requiring extra work just to get in and out!

**shady milkman** · 04-14-2009, 04:32 AM

Originally Posted by boosted z

i can take the alt back and get a free replacement, but should i try to get the cash back and put it on a higher amp alt, the free one i would get is a freakin reman......my car has the alt on the bottom of the motor bc of the blower so it makes the wiring even worse.

all f-bod ls1's alts are on the bottom

**BowTied** · 04-15-2009, 04:05 AM

That is what I was thinking. Nonetheless I went out to see if there was a Super Charger in there I HAD BEEN OVERLOOKING!

Nope, Christmas in April...ruined!