Charging system frying alternators

ashley brown · Dec 13, 2017

I have a 98 gst that has been blowing alternators I mean frying them the last one I put in (which is number 5) was fried to the point you could smell it I took it to the dealership and they kept telling its the alternator. When this first started I had a cam sensor go out. Mind you it took my car three weeks to finally run the code but only did it cause my battery was dead. Changed the sensor then went to replace the alternator since it failed. Put a new one in and the battery light and brake light still stayed on but once you start the car the lights go off and I haven't had them come back I've put three more in since then and the last one actually fried unlike the others they just failed. I have another one in but am afraid its going to do the same thing my car needs emmisons done by the end of the yr for tags been down since may I've changed the battery twice along with ground wires the alternator fuse the relay fuse and still the lights stay on in acc mode but go off soon as the car starts also when I come to stops the rpm needle starts to jump around and the motor acts like its misfiring and wants to die but only at stops it really does this to where you have to hold that gas to keep the rpms above 1k its done it a couple times while driving down the re but found its only after getting off the highway (driving 35 miles) please help really need my car running used as a daily has some mods but mainly bolt on no tune anymore as of two yrs ago

Spector5 · Dec 13, 2017

Does it appear anyone has done previous wiring repairs anywhere in the alternator circuit?

Also, I’ve never experienced it, but a lot of guys have had heating issues. The alternator gets to hot from the exhaust/o2housing. They either build a heat shield or relocate the alternator.

-another possible thing you can eliminate off the bat. Notice a power steering leak or fluid on the alternators you’ve replaced?

Dstarperformance01 · Dec 13, 2017

Have you checked all fuses and grounds?

ashley brown · Dec 13, 2017

All fuses and grounds are good replaced the ones off the battery they were a Lil chewed up. I was told the power steering is leaking a Lil which ok but the alternators are frying as soon as I stick the key in and turn it to acc mode

Turbo2g · Dec 13, 2017

How old is your battery? Is it the right one for the car? Test it and make sure it passes a load test too. A bad battery will cause an alternator to work hard all the time, thus burning it up. I'd start there. Also what brand of alternator are you using? Duralast from Autozone because its the cheapest? You will keep going through garbage parts if that's what you are using.

I'm assuming you replaced the alternator at one time due to finding a weak or no start. At that time did the battery get a proper charge from a battery charger? Or did you just throw the alternator on and go? It is very bad for an alternator to try and revive a dead battery. You may be killing them just by the fact that the battery is weak.

lasershark · Dec 13, 2017

ashley brown said:
I've changed the battery twice along with ground wires the alternator fuse the relay fuse and still the lights stay on in acc mode but go off soon as the car starts

This is normal, with the key in the acc position, the battery light is supposed to illuminate.

Also, fix the power steering leak, the fluid murders alternators unbelievably quick.

chrysler kid · Dec 13, 2017

Yeah the battery light should always come on when the car is off. That is a sign that the light bulb works

The light bulb is a resistor that is wired into the alternator to tell it what amperage to put out.

Have you actually had the alternators tested at the auto parts store

joemamma · Dec 14, 2017

do u have a dvom?

ashley brown · Dec 14, 2017

Turbo2g said:
How old is your battery? Is it the right one for the car? Test it and make sure it passes a load test too. A bad battery will cause an alternator to work hard all the time, thus burning it up. I'd start there. Also what brand of alternator are you using? Duralast from Autozone because its the cheapest? You will keep going through garbage parts if that's what you are using.

I'm assuming you replaced the alternator at one time due to finding a weak or no start. At that time did the battery get a proper charge from a battery charger? Or did you just throw the alternator on and go? It is very bad for an alternator to try and revive a dead battery. You may be killing them just by the fact that the battery is weak.

Battery is brand new replaced it with the alternator and is still sitting at 12.3 when off and back to 13.8 when running. And LOL

no my alternator is not from ghettozone I got it from napa. Each time the battery was tested when this all first started it failed so I got another one from sears has a 3 yr on it better than the parts store with only a 1yr so I know the battery is good also just tested it yesterday when I put the new alternator in since its been sitting for over a month without running but is,still ok I haven't hooked the alternator up yet tho its just bolted in

lasershark said:
This is normal, with the key in the acc position, the battery light is supposed to illuminate.

Also, fix the power steering leak, the fluid murders alternators unbelievably quick.

The lights stay on tho they dont shut off like the rest of the lights sry I didnt mention that in the post but yes they dont go off til u turn the car on

chrysler kid · Dec 14, 2017

ashley brown said:
Battery is brand new replaced it with the alternator and is still sitting at 12.3 when off and back to 13.8 when running. And no my alternator is not from ghettozone I got it from napa. Each time the battery was tested when this all first started it failed so I got another one from sears has a 3 yr on it better than the parts store with only a 1yr so I know the battery is good also just tested it yesterday when I put the new alternator in since its been sitting for over a month without running but is,still ok I haven't hooked the alternator up yet tho its just bolted in

Napa and AutoZone and oreillys alternators all come the same factory in mexico.

AutoZone and Wal-Mart are the only places that sell batteries with a 5 year warranty. Napa oreillys AutoZone, Wal-Mart, diehard, are all made by Johnson controls for those companies.

Your battery should be at 12.5 volts or higher if it is being regularly charged, 12.3 is low for a car driven regularly

So I'll repeat myself, have you taken the car up to the auto parts store to have them do an alternator test on your car while the car is running? Oreillys and AutoZone do those test for free, in not sure if the Napa guys come out from behind the counter they might not test them on the vehicle

ashley brown · Dec 14, 2017

chrysler kid said:
Napa and AutoZone and oreillys alternators all come the same factory in mexico.

AutoZone and Wal-Mart are the only places that sell batteries with a 5 year warranty. Napa oreillys AutoZone, Wal-Mart, diehard, are all made by Johnson controls for those companies.

Your battery should be at 12.5 volts or higher if it is being regularly charged, 12.3 is low for a car driven regularly

So I'll repeat myself, have you taken the car up to the auto parts store to have them do an alternator test on your car while the car is running? Oreillys and AutoZone do those test for free, in not sure if the Napa guys come out from behind the counter they might not test them on the vehicle

All this,was done while it was at the dealership and all they could tell me its the alternator and that I needed to pay 650$ to have the order me the OEM one and along with three hrs labor. There's something in my car thats causing them to blow there's no way in hell all 5 alternators are bad one after another after another right as soon as the power is hooked up to them

chrysler kid · Dec 14, 2017

ashley brown said:
All this,was done while it was at the dealership and all they could tell me its the alternator and that I needed to pay 650$ to have the order me the OEM one and along with three hrs labor. There's something in my car thats causing them to blow there's no way in hell all 5 alternators are bad one after another after another right as soon as the power is hooked up to them

Exactly
So how do you know the dealership wasn't messing with you. They saw a rebuilt alternator and blamed the part.

Have Napa or AutoZone test the battery and alternator

ashley brown · Dec 14, 2017

chrysler kid said:
Exactly
So how do you know the dealership wasn't messing with you. They saw a rebuilt alternator and blamed the part.

Have Napa or AutoZone test the battery and alternator

They have both been test just yesterday right before I put the alternator in and the battery is good n the alternator is good right now til I turn the key to acc and or turn the car on I dont even drive the car and it blows the alternator each time they are tested before putting them in and they test passing and then I turn my car on and they are bad

chrysler kid · Dec 14, 2017

Well then your wiring to the alternator is bad. It might be the connector to the alternator is damaged, or ive also seen the 02 sensor touch the main power wire

You will need to get a volt meter and download the pin out diagram of the connector to the alternator. You then need to test the wires in the connector to see which wire is shorting the alternator

ashley brown · Dec 14, 2017

chrysler kid said:
Well then your wiring to the alternator is bad. It might be the connector to the alternator is damaged, or ive also seen the 02 sensor touch the main power wire

You will need to get a volt meter and download the pin out diagram of the connector to the alternator. You then need to test the wires in the connector to see which wire is shorting the alternator

Ok I also did change the plug that goes from the harness to the alternator my last one did have a wire that was kinda sticking out from the plug itself found one from another car the harness doesn't show any melting or anything like that the plastic cover is still in good condition its just weird cause all I did was change the cam sensor wasn't having any problems prior to this changed the sensor and the alternators are just frying now

chrysler kid · Dec 15, 2017

Yeah that shouldn't have caused any problems.

Its unusual for any alternator to fail like that and grenade itself. The only explanation is that the alternator is receiving a drastically reduced input signal to the regulator telling it to discharge as much amperage as possible.

To be thorough, make sure the power wire (those 2 white wires ) aren't cut or pinched anywhere. They loop down under the motor by the oil filter housing and then back up the radiator support by the fans if I remember correctly

ashley brown · Dec 15, 2017

chrysler kid said:
Yeah that shouldn't have caused any problems.

Its unusual for any alternator to fail like that and grenade itself. The only explanation is that the alternator is receiving a drastically reduced input signal to the regulator telling it to discharge as much amperage as possible.

To be thorough, make sure the power wire (those 2 white wires ) aren't cut or pinched anywhere. They loop down under the motor by the oil filter housing and then back up the radiator support by the fans if I remember correctly

The two white wires look good I didnt see any burn marks and the connectors I replaced them the harness that runs under the radiator also looks good

Vegas Smith · Dec 15, 2017

The alternator system is very simple. This must be some kind of short. In short (pun intended), just redo all the alternator wiring and leave the stock wiring there.

lil_dsm69 · Jan 13, 2018

So idk if this is a bad or dumb question but since this all started the only thing I replaced or touched was the cam sensor I replaced that and now I have this alternator problem would the cam sensor being not oem would it cause a problem in the charging system?

motomattx · Jan 13, 2018

No. The two thick white wires run from the back of the alternator to the fuse box, they run under the core support, pull that loom out and see if the wires are bare or melted somewhere under there, if nothing else run brand new wire all the way from the alternator to the fuse box, you have a short or partial short its that simple.

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