alternator issues
 

Hey guys, I have a friend of mine (who isn't very forum savvy) who is killing alternators left and right.

He has been killing one, once a week almost. The car is turbocharged, but no other crazy electronics (minus the megasquirt and gauges).

He's gotten a remanned alternator, and I've read that a few people have had issues with the reman units, but it doesn't make sense to me to be through three of them back to back.

Each time the car stops charging, but the charge light never comes on. The car is a 95 M edition.

Does anyone know where I should start checking first?

If there is resistance at the connections then the alternator will be working way too hard all the time and will burn up. Take some sandpaper and clean the connection at the rear of the ppf where the main battery ground cable attaches to the ppf. Then do the same for the connections from the back of the engine to the firewall and for the alternator to the main fuse block near the windshield wiper motor.

I actually went further and added an additional 6 gauge wire from the alternator to the battery with a fuse and likewise supplemented the wiring from the alternator to the main 80 amp fuse with a 6 gauge wire just for good measure since I have an aftermarket fuel pump and Spal fan and air conditioning. I also added a ground wire from the ground connection next to the throttle body over to the frame rail. Some portion of this is probably overkill but everything runs much better now.

I had bad luck with Bosch aftermarket alternators, if that's what he's using.

I went over to his house the other night with my multimeter.

All the fuses are good (main, fuel injector, and the meter inside the car). It was charging when I went over there. But I disconnected the two wires from the alternator, and the charge light didn't come on, however it continued to charge for some reason.

Both wires when the car was running showed 14v's. Turned the car off, and one wire had battery power, and the other had nothing. Turned the key on, and both wires showed battery power, and while the engine was off, the charge light wasn't on either. But the CEL and everything else was on for the bulb check.

In the wiring diagram it shows two DIODES coming from either side of the charge light. I wonder if it's possible that the diodes have gone bad?

What MS does he have? If he built an MS, then he NEEDS NEEDS NEEDS some sort of alternator control. It might idle and make 14V, but as soon as he starts to drive he'll make 18V.
I think the MSPNP2+ has alternator control built in. I'd check its settings to see if something got changed.

DIYMS2PNP.

I thought the NA"s were externally regulated?

Na cars are internally regulated NB cars are externally regulated