Alternator Stupidity.

[Dbeck002]

Couple days ago when I ran the camaro we did runs from about 5 mph to 110. We did 4 total and on the 4th run right when i let off my battery light turned on, i saw my voltage drop but the car stayed running. Voltage did not fluctuate when revs did so i knew the alternator was fried. this alternator is giving me a lot of problems, its a 150 amp 3G alternator, its supposed to last... this is the second time it fried on me, and the first time wasnt even because i was racing.


So i replaced it with a spare stock replacement alternator. and the car runs ok and the batt light turned off but i still need the higher amperage alt, this stock one isnt gonna handle my radiator fan. Why does my 3G keep frying!!!!??? crapola

 

[HISSIN50]

What part of the 3G fried? Was it internal or the regulator (which is replaceable).

 

[Dbeck002]

Well the first time it fried i sent it back to the company under warrantee. i dont know what caused it to fail the first time, they sent it back and it ran fine until a few days ago when i was racing. It shouldnt have fried again though.

I know things are replacable but my intention is to have a functional alternator without having to replace fried diodes or regulators left and right. I dont know why its only happening with the 3G, that alt is supposed to be beefcake.

 

[Dbeck002]

Anybody encounter these problems?

 

[Dbeck002]

I really need some ideas guys. Even if its a longshot, tell me your stories. Because if i keep frying alternators im gonna flip out. Why does my 3G always fry on me!!!

Should i replace the whole ECU circuitry with a Painless setup? Could it be something internal of the ECU that is doing this? The alternator was brand new.. grrr.. crapola

 

[jrichker]

At some point the alternator is either losing the sense voltage that it uses to
regulate the output or is losing ground that connects it to load.

The secondary power ground is between the back of the intake manifold and the
driver's side firewall. It is often missing or loose. It supplies ground for the
alternator, A/C compressor clutch and other electrical accessories such as the
gauges. Any car that has a 3G alternator needs a 4 gauge ground wire running
from the block to the chassis ground where the battery pigtail ground connects.

See the following website for some help from Tmoss (diagram designer)
& Stang&2Birds (website host) for help on 88-90 wiring

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

Diagram courtesy of Tmoss and Stang&2birds.

 

[Dbeck002]

 

[mustang-a-holic]

What is your pulley size on the alt. ?

 

[time only]

I burned out 2 of those alternator before I was told it might be a electric spike in the systems,I replaced the battery as recommand and have no problem since.

Hope it work for you...

 

[Dbeck002]

I have UD pullies but never had the problem before with the stock alt. I have a stock one in there now just so i can get around but i dont know how long it will last.


BTW i just added a ground from my block to the chassis and it made a huge difference in the voltage reading. Even with the stock alt i can tell its much better. I just need to buy a new regulator, does anyone know where to get regulators for the 3G alternator? I remember someone had posted this link before, but it was a long time ago. They run around 35$ if i remember correctly. I could use one...

 

[HISSIN50]

I think LRS sells them for 35 bucks or so. And Monte Smith has a lot of good regulator and part info on his article.

Good luck.

 

[Dbeck002]

I PMed him, does anyone have the link to that site that sells the regulators?