2.7l 1995-1997 Alternator/Charging Issues.. Read This!!

I have been chasing a charging issue for a couple weeks now and finally figured it out. Trucks produced on or before April 1997 require a different alternator from the trucks produced after April 1997. I didn't look into the differences that much but pre-April trucks seem to have a slightly different rectifier and put out 80amps. Post April trucks only 70amps.

I was about to pull my hair out till a very helpful employee at NAPA pointed out that the back side of the alternator (both apparently fitting 1997 trucks) looked different. After a little more research and a new alternator, PROBLEM SOLVED. Alternators are a regular maintenance item so I figure I would spread the word.

I attached a screen shot from Rock Auto and the only manufacturer that notes the difference is Beck/Arnley. Notice Rock Auto doesn't carry the correct alternator for pre-April 1997 trucks.