need help diagnosing an electrical issue - NJFBOA - Home of New Jersey's Camaros and Firebirds

madness410 · 07-15-2016, 11:56 PM

im 99% sure this is the alternator but before i go dumping money into it i'd like to get your take.

99 ws6 148k miles. not sure when the alternator was last replaced. lately the voltage meter has been fluctuating, i didnt think much of it because with the heat ive been blasting the air.

today i was driving and the voltage was low..and as i was driving it got lower..and lower..and lower, then i lost all electric, the guage cluster looked like a christmas tree with blinking lights everywhere... and then the car died. luckily i had a friend nearby who jumped it, 30 seconds later, while idling...died again. was able to limp it back home but had to jump it twice before getting it home, with it being dead each time.

a few weeks back i had an issue with no start and to rule out the battery i had it tested and it came back ok. it was the starter which i replaced, the battery i think would be ruled out. when its hooked up to another battery it starts right up and idles fine.

so replace alternator? thanks for all your input in advance..

Jersey Mike · 07-16-2016, 07:31 AM

A member on here, donnj, taught me a trick that I've used quite often the last few years:
With the car already running, disconnect the positive terminal on the battery. If the car continues to run, the alternator is OK. If the car dies, then you have an issue with your alternator.

My crude understanding can be condensed down to: "Battery just starts the car, alternator keeps it running."

In the meantime, charge your battery so you can get to an Advanced Auto or the like, and have your alternator tested for free. I once drove 52 miles to work on a fully charged battery, had a gas station mechanic charge it during my 8-9 hours at work, then drove the car 52 miles back home

(it was a Friday and I couldn't do the repair until Saturday

)--Point being, charge the battery as a temporary band-aid to get you to the nearest part's store that can test the battery, alternator and starter for you.

V · 07-16-2016, 08:52 AM

Seems like it is the alt but from what I've experienced, jumping a car with a bad alt the car will stall as soon as you unhook the cables. A bad battery will let the car run. The battery could be shorted and causing the issue as well.

sweetbmxrider · 07-16-2016, 10:13 AM

Most likely the alternator since you lost voltage while driving. Might have been temporarily getting juice out of it after jumping or if you left the cables on for a bit, ran off of the charged battery. Don't these cars fall victim to power steering pumps leaking onto the alternator?

madness410 · 07-17-2016, 10:26 PM

I bought a new alternator ill put it in this week. I'm pretty sure it's the alternator. if not at least I have peace of mind putting in a new alternator for the future. it's a 17 year old car I'm not sure what has been replaced and what hasn't.

as far as the alternator location yes in gm's infinite wisdom they placed it directly under near the power steering pump. allegedly from what I've researched it's a myth that dumping power steering fluid on it can't hurt it.

madness410 · 09-02-2016, 11:04 PM

ok to add to this I had another electrical issue tonight. I installed that alternator and has been working perfect since.

drove to a local bar tonight and parked it, voltage when I parked it was around 9 but was at 12-13 or so all the way there. I left and I started the car the voltage was around 8. I was hesitant about driving so I burned some time debating about what to do. checked cables and connections. the car started fine a few more times same voltage. the headlights and all electrical components were on perfect as if the voltage wasn't low.

so after building up the balls to drive 13 miles home all dark roadways, I decided to do it. I made it back to my development and the battery completely died. voltage was at 8 or so the whole 13 mile trip back to the development.

when I replaced the alternator a few weeks back I had the battery checked and they said it held a charge just fine. but now I'm thinking between then and now the battery took a crap. but now I'm reading coil packs could take a crap too and have similar symptoms. and if the cause was the battery why would the car start several times. before I dig into it again I was wondering of your guys opinions.

sweetbmxrider · 09-03-2016, 08:46 AM

I would have a shop load test the alternator in the car. If you have a voltmeter, a charged battery resting should have about 12.5 volts and while the car is running you should see about 13.7-14.2 with no accessories on. Haven't heard of coil packs causing your issue.

madness410 · 09-03-2016, 08:59 AM

ok I will check that. the battery is totally dead now I will have to charge it. when I installed the alternator the excitor wire popped out. I bought a new one and spliced it into the harness using a butt connector. I will check that today as well.

madness410 · 09-03-2016, 11:13 AM

weird I went out to the car today and it fired right up but still held at 8 or so volts according to the dash. even after it completely died last night on my way home.

sweetbmxrider · 09-03-2016, 04:03 PM

I'd triple check that wire. If its not making a proper connection, the alternator won't charge. Ohm out on either side of the connection and wiggle it around.

xrelapse13 · 09-09-2016, 01:04 PM

I'd double check the connection on the exciter wire, it's critical to the alternator properly working. Also, if you by chance have to replace the alt again, i'd recommend going with the truck 145amp one. It's a direct fit/replacement and works significantly better, especially if you like to run ac/music, etc.

Have the alt and batt retested, could have gotten a crappy remanned alt.

madness410 · 09-10-2016, 05:14 PM

thanks adam and rob. i havent had time to dig into this yet but once i do the alternator and battery will both be pulled to be tested. i heard that some auto parts stores sometimes test alternators that still show that alternators are fine but really they are junk and broken.

rob if the alternator is the culprit would you happen to have the part number off of the 140 amp alternator? the direct replacement. i do have a system in my car its just 1 10" i figure if im going to need to replace it might as well get a higher amp alternator.

ar0ck · 09-11-2016, 12:34 AM

Quote:

Originally Posted by madness410

thanks adam and rob. i havent had time to dig into this yet but once i do the alternator and battery will both be pulled to be tested. i heard that some auto parts stores sometimes test alternators that still show that alternators are fine but really they are junk and broken.

rob if the alternator is the culprit would you happen to have the part number off of the 140 amp alternator? the direct replacement. i do have a system in my car its just 1 10" i figure if im going to need to replace it might as well get a higher amp alternator.

Take those Store tests with a grain of Salt, I took mine a few weeks back and although it tested fine on their Machine, a volt meter on the actual Alt & system with the car running said other wise.

madness410 · 09-16-2016, 03:25 PM

so I dug into it today. immediately recognized the problem. when I took the alternator out the power cable that bolts to the back was hanging on by a thread. when I undid the wire loom the wire was melted about 3 inches up. my idiot self now remembers when I took the alternator out in the first place the connector that connects the wire to that bolt I took one out of my toolbox I didn't even think about wire guage. I'm not sure what guage that one was rated for but I bought a new one rated for 6 guage.

I ended up upgrading the alternator anyways to a 145 amp since I thought the alternator took a dump I went out and got that one at a junkyard and was an oem part not a reman. so far so good. voltage is back to normal. the voltmeter shows lower voltage than I'd like at the battery at 11.6 or so. when idling the voltage at the battery is 13.6 or so.

so for now another 4th gen ls1 is on the road hopefully the car needs to be driven a bit more to get the voltage up on the meter.

sweetbmxrider · 09-17-2016, 09:59 AM

In all reality, you should run much larger wire. They refer to it as the big 3 upgrade. Bigger leads to the starter, alternator, and fuse block. Use the same size wires for the grounds from the battery and one between the motor and car and your voltages will be much better. Something to think about.

madness410 · 09-17-2016, 01:45 PM

yeah I saw that on tech I do plan on doing that upgrade in the future especially with this wire idk if it's damaged further from where it I cut it off where it appeared to stop melting. so far it's working ok.