:banghead:

Yes, this IS a long post, but this problem requires a complete explanation.

1993 Eclipse GSX - Completely Stock

Over the last year and a half, I have replaced the alternator 7 times! The original alternator lasted for 160k miles. The first replacements
lasted about 3 months before failing. Replacement units then began to
fail faster and faster until the last unit failed within 3 or 4 days after installation. Each and every time, the internal regulator of the alternator failed. Just before this happens, the dash lights get brighter than normal and within a day or two, the alternator stops outputting the 14.2 charging voltage. I am certain that the alternators I am using are of good quality and the correct rating.

I have done the following:

- Replaced the battery twice - brand new both times
- Checked for shorts and high resistance on associated cables and wires.
- Performed all tests shown in the Chilton's and AllData references
- Installed alternators from 3 different remanufacturers.

The only odd thing that I did find and NO ONE can explain why is that the "idiot light" for the alternator/batt illuminates with the ignition switch
in the "on" position, but has never illuminated during any of the alternator failures. I find this quite interesting and wonder if this may be a clue as to what may be wrong with the charging system.

A Mitsu dealership suggested that the ECU may be the cause but I am not totally sold on this idea. The dealer also told me that the ECU contains the actual voltage regulator for the vehicle and what is inside the alternator is just a series of diodes and not specifically a regulator. Has anyone ever heard of the ECU repeatedly taking out the internal regulator in the alternator?

Am I missing something? Any suggestions would be greatly appreciated.

Kim

The ECU wont be causing bad alternators, and the regulator isnt in there. I would have heard that before if it was I'm sure. Plus I cant think of one good reason why it would be there. A bad ECU however can cause similar symptoms as a dying alternator, but the charging system will still be functioning of course.

Rebuilt alternators are notorious for being bad. On average you need to go through about 5 of them to get a good one. Switching brands may be throwing off your odds of getting that 5th good one :lol:

you dont by chance have a fairly nice stero system do you, with a couple amps?

I have been through 7 alternators and now going on number 8. I have ALWAYS used rebuilts in the past with other cars and NEVER had a problem like this.

I spoke to an ECU tech and he said that some of the older model Eclipses had ECUs with the regulator inside the unit - but this is not the case with my car.

The nightmare continues . . . .

Thanks for the feedback

This car is completely stock - Original Radio/CD Player and no electrical mods . . . .

the voltage regulator is in the alt. Cuz my ALT. went bad about 4 months ago and i had it rebuilt.
It was the regulator that went in it and burned the windings up so i had it rewound to 150 amps to power my stereo better have not had problems since.

You know, I had the same idea about overbuilding the damned thing to handle whatever load is causing the regulator to fail. At least I could identify the problem by following the smoke trail! :)