93 sc mitsu or ford alt (overcharge)

89tird

Registered User
i just installed this rebuilt altenator i got yesterday from a local shop my old one stopped charging, it looked just like my old alternator but the mouting holes didnt align so the guy put the old nose in. he tested it in front of me it was reading 13.6 to 14v and 110 amps.

jump started the car and checked the reading on the battery it was reading 13.5v let it run for like 10 minutes 13.6v moved the car a couple of feet and parked it back.. then i started hearing my ic fan run faster and louder and saw the alt cable that goes on the starter solenoid smoke. checked voltage and it was at 16v ??

could it be something else or did this alternator go bad too ??
 
i thought the same thing, but the guy showed me test and it was reading good.. maybe it's because didnt leave it hooked up long enough ?
 
i thought the same thing, but the guy showed me test and it was reading good.. maybe it's because didnt leave it hooked up long enough ?

Well for starters, was it the guy that rebuilt that showed you the test? What was the test done on? I have used the VAT machines, they are pretty common for electrical testing. I don't know of one ever giving me a result on the regulator, it was always pass/fail. And I don't know if they are set up to detect overcharging. I assume the 16 volts was measured on a multimeter? Let's break this down:

1) Short of a freak one-in-a-billion electrical malfunction that somehow INCREASES the voltage without frying the whole system, and happens when the alternator is rebuilt, there is nothing else in the electrical system that would raise the voltage.

2) The electrical system is reading high and acting funny. Can't ignore that and go by "it tested OK", again from the guy who rebuilt it I assume.

Unless I'm missing something, it's still a bad alternator. I'd have them redo it, or get my money back and just buy a reman one from a parts store. Don't get a cheapo reman, I've seen them be bad out of the box. Get one from NAPA or Advance or whoever you have there who is good.
 
ya he rebuilt it, he used an alternator test bench dont know what kind, some old machine.

but i just remembered something the alternator i gave him was overcharging my old battery i guess it was a mitsubishi unit because it said made in japan, the one he gave me said made in japan also and it overcharged my battery too.

the one that just died on me was a ford unit i pulled out from a 94 supercoupe at the junkyard , maybe the japan ones have more amperage than the ford units.

do you know if a 93 sc came with a mitsu or a ford unit from factory ??
 
do you know if a 93 sc came with a mitsu or a ford unit from factory ??

SC alternators are a Mitsubishi brand alternators. Always have been. It is an internal regulator design. If it wasn't overcharging, and then it was, something failed in the alt.

The mitsubishi alternators are quite sensitive to overheating. If you have a dead or lower battery and try and use the alternator to charge it, you'll likely overheat the alternator.
 
then i started hearing my ic fan run faster and louder and saw the alt cable that goes on the starter solenoid smoke. checked voltage and it was at 16v ??
Tell him the story.. the regulator is bad. And yes, he needs to run it for a long time and under a load to get it to repeat. This is sort of the issue with remans.. they don't/can't really do whats known as a burn-in test and from my experience, more than 1/2 the reman's wouldn't pass..:eek: Unfortunately..the alts operate under high heat and load for long periods of time.. so a burn-in needsto be done or its just dumb luck that it works. :(
 
yep i think i burnt it trying to recharge my dead battery... im going to try to get a different one tomorrow.

any idea why 94 sc's have a ford instead of a mitsu unit ??
 
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