Last night the brake, ABS, Battery, and Temp. lights came on. Sometimes they would turn back off when I hit the brakes. The display screen in the center of the dash flashed a warning 'irregular voltage,- system will shut down in 7 seconds' and shut itself off for a couple minutes and come back on. It repeated this several times before I got home. The vehicle functioned normally. The only possible odd thing was that possibly the head lights were brighter than normal. I was driving through a rain storm so it was hard to tell.

This morning I put a volt meter on the battery, which is only a few months old. Battery while not running was 11.3 which indicates to me it was drained during my drive home. When I first started it up it registered 14.5 - 15.5 and there were no warning lights on the dash. After a minute or two the warning lights came on and the voltage fell to 12.

Thats the only thing I had time to do. I looked at the fusible links next to the battery and they appeared fine.

I'm thinking the voltage regulator on the alternator is shot. What else should I check before I buy a new alternator?

 

id say you got it in one.
Battery should rest at 12.2-12.8, charge at 13.8-14.8

 

It does sound like a voltage regulator failed. Check to see if you can replace only the regulator instead of the whole alternator. Should be much less expensive

 

Thanks!

Anyone know the amperage specs on an oem alternator? Mitsubishiparts.com doesn't list any details. They do sell the voltage regulator separately but it will only save me ~$40. Others listed on the net range from 80 amps to 150.

 

It's 100 amps. Ordered a 100amp raylock with a 3 year warranty from NAPA. After core refund it will only be around $80 and will take longer to pick it up than it will to replace.

 

Just thinking from other forums, could your failed alternator be caused by a leaking cam oil seal? Might want to check as it could easily ruin the next one.

 

Good call. If you have oil leaking on top of the new alternator, your problems will be right back.