Owners of other General Motors Buick, Oldsmobile, Chevrolet or Holden vehicles equipped with the GM 3800 Series II V6 engine from 1995 to 2005 may also find these alternator replacement instructions useful.

My alternator gave up on me on the way back from Home Depot with a utility trailer attached. I guess that the stereo system, trailer lights, headlights and hazard lights on all at once was too much for the old OEM part to handle.

To be sure, I hooked up the battery to a "Battery Tender Jr." 12V trickle charger over night. The next day I was able to complete a couple of errands before the battery light illuminated on the dash. Once back home, the car wouldn't start again without a jump.

I also knew that my battery was less than 6 months old so all signs pointed to the alternator needing to be replaced.

Check out all of the replacement alternator options at Amazon.

Some of the vehicle models that have the L37 N/A (naturally aspirated) or L67 S/C (Eaton M90 supercharged) versions of this popular engine include the Bonneville, Grand Prix, Grand Am, Park Avenue, Regal, Century, LeSabre, Riviera, Cobalt, Malibu, Intrigue, Ion, Firebird, Lumina LTZ, Commodore, Monaro, Eldorado, Seville STS, Deville, Cadillac DTS and Chevy Monte Carlo SS.

I'd imagine that the newer 2004+ cars with the GM 3800 Series III L26 N/A and L32 S/C engines might also have a similar alternator replacement procedure.

A few compatible replacement alternators with their part numbers are as follows: ACDelco 335-1078, ACDelco 334-2487A, DB Electrical ADR0138, TYC 2-08437, Remy 91531 and Quality-Built 8243605N.

If you can't read the accessory serpentine belt routing guide on your car, I have provided a copy above.

At first I mistakenly loosened the supercharger belt by attaching the 15mm socket & wrench to the tensioner near the front of the engine.

The correct tensioner for the alternator is just below the ALT pulley.

In order to get the wrench and 15mm socket onto the tensioner pulley below the alternator I had to remove the coolant overflow / filler tank and also my aftermarket Buick GM STB (strut tower brace).

At this point, go ahead and remove the black negative (-) battery terminal for safety. My battery required an 8mm socket to remove the terminal.

Then I had to remove the nut on top of the black bar end which covers "Bolt # 2".

To move the black brace bar off of the alternator, locate the other bolt on it that secures it to the engine (Picture # 31) and loosen it a bit.

Then you can lift the black brace bar off alternator bolt # 2 and remove it.

Then I popped off the electrical connector on the bottom right hand side of the alternator.

After calling AutoZone, Discount Auto Parts, and Pep Boys, I found a remanufactured Bosch alternator at PepBoys for $140.99 with a $15.00 core return charge.

Don't forget to connect both the electrical connector and the power lead cable.

The documentation that came with the new alternator warned that a weak or dead battery could damage the alternator, so I attached my battery again to the Battery Tender Jr. 12 volt trickle charger over night till the little light went from red to fully charged green.

They'll usually do this for free.

You could also test the alternator and battery yourself with a voltmeter.

With the car running, the voltage across the battery terminals should be anywhere from 13.8 to 14.8 volts.

For more, check out all of my Pontiac Grand Prix DIY Repair & Maintenance Guides.