My alternator is toast! HELP ASAP (what ones will fit?)

Matt94GT

Registered User
I need a alt asap for my 90 Tbird SC. What ones will work? Any alts from 3.8L or what? I just need it to work, I read that 110 is stock will a smaller one WORK?

Im pretty sure its my alt, I put in a battery out of my other car which was dead, jump started it and it ran fine, drove around for a good 15 minutes running great, shut her down and It wouldnt start, didnt have enough juice.

THANKS SO MUCH!
 
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You can pickup a used SC alternator pretty cheap (check the classified section). I know the SC uses a higher amperage alternator than the 5.0 t-birds and the same is probably true of the 3.8 NA.

David
 
Make sure to get a voltage reading across the battery terminals when it's running. If it's below 13.8-14.4 (or so) volts, then yes, your voltage regulator in your alternator is probably shot. I have read in the past that "new" (rebuilds) from local parts stores do not last very long, but I would venture to say that if I was in the same situation, I would go to the for sale forum and contact someone who has an alternator for sale. Good luck.
 
I paid $100 to a local rebuilder to have my alt rebuilt. Actually he gave me a different rebuilt unit since mine had damage that wasn't worth fixing. But at $100 it was well below the rebuild alternator costs at local parts houses. I also have a higher level of faith that it will work a while.

Check around, I bet you have a shop that will rebuild it. The shop I found specializes in rebuilding electrical motors and big alternators and generators from heavy trucks and other machinery like Gen Sets. But they also did car alternators.
 
Matt94GT said:
I need a alt asap for my 90 Tbird SC. What ones will work? Any alts from 3.8L or what? I just need it to work, I read that 110 is stock will a smaller one WORK?

Im pretty sure its my alt, I put in a battery out of my other car which was dead, jump started it and it ran fine, drove around for a good 15 minutes running great, shut her down and It wouldnt start, didnt have enough juice.

THANKS SO MUCH!

If the battery you put in was dead when you put it i the car and the car ran fine after a jump start, then the alternator is definitly putting out enough power to run the car. As mentioned, check the voltage while the car is running. I'm kinda in the same boat with my car right now nd haven't found a solution next. If I drive around on longer freeway trip, it's fine, but stop and go city driving and it will do the same thing as yours. The battery dies and I am unable to start the car without a jump start, but runs fine once it starts. I can charge the battery up with my battery charger and it will be fine for a couple days, bu then die again.
 
Jump starts won't tell you much as a battery can develop a slight surface charge and the car run fine depending on how long you let it charge up before starting.
Buy/borrow a volt meter. Its the only way you'll know whats happening. The results are easy to interpret: if it reads 13.8-14.4
volts with the engine running, everythings fine. Anything else means the alternator is weak or broken. Anything below 12V means the battery is being drained.
Also, clean the battery posts and clamps with steel wool even if they don't look dirty :cool: and charge the battery up fully with a trickle charger and test its charge state with a bulb type battery tester (cheap tool).
 
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