Noisy Alternator
 

OE alternator finally went to ghost on me over the winter. I bought a new one from NAPA, put it on, and went for a drive. Kept hearing sirens around me the entire ride. Every stop sign I was looking for where the siren was coming from. Drove me crazy... I was beginning to think I was being punked.

Finally realized the new alternator was whining bad. After a week of driving it was no better, so I took it back and got a replacement. This one was almost as bad. Decided to just live with it until if finally warmed up around here and I'm driving with the windows down. Had to laugh when the wife started looking for where the siren was coming from when we stopped at a light.

So, feeling like a bit of a candy ass for taking another alternator in because it's too loud when I have my windows down. How can I tell if it's the bearings I'm hearing, or if it's internal? I'm hoping if it's just bearings i can take it to a rebuild shop...

Thanks

Had the exact thing happen on my '98 F150. Factory crapped out at 100K miles. Got one at NAPA. About 3 months into that one it started making noise and the rear bearing went out. Thank God I had my receipt...NAPA replaced it at no charge under warranty. The NEW new one started to make some noise but I have traded it now and it is someone elses problem.

Sounds like NAPA has problem alternators.

I think on this new 2007 F150...I'm going with Motorcraft stuff when I need alternator, batteries, hoses, water pump, etc.

depending on what alt you have there are rebuild kits on the net for them to rebuild them stock all the way up to 200 amps or more depending on what alt you have i found kits for my 6g for $140 to upgrade it to 200 amp comes with all bearings and parts needed the same sit had just the bearings for the stock alts and any other peice you needed to fix them.
http://www.springhillautoelectric.co...d&productId=50
this is the website youll have to find your type of alt but they have parts for all ford alts i think.
maybe cheaper than napa idk though. but arent napa units just old rebuilt alts?
there are also diy videos on rebuilding these ford alts that show you step by step how to do it. well if you have the time and tools but from watching the vids it doesnt look to be a very involed task at all pretty simple.