I got a '94 F-150 w/5.0 and auto. I recently replaced the battery because it wasn't holding a charge. It was okay for a few weeks but now it's acting up again. I charged the battery and left it unhooked for a few days and when I hookt it back up, it(the battery) seems fine. So I'm guessin that the alt. isn't charging correctly.
When I have the engine running at idle the battery guage is on the low side and it jumps around alot, without adding any load. When I turn everything on (lights,fans) it gets even lower but dosen't jump around as much. I have always disliked the way the headlights dim at idle. So I am hopin to kill two birds with one stone by gettin a better alternator.
I think these trucks have a built-in voltage regulator (I may be wrong) or I would also be wondering if that is bad.I may just need to pull it out (the alt.) and have it tested.
Any diagnostic advise would help, but the other ? I had was if there is any upgrades i could make if I do need a new alternator.(MORE POWER). I think the one in there is the stock 60amp or somethin one.

 

I actually think it is a 95amp alternator that is in there right now. I have read on this site that the 200amp is the one to go with. Is this right? I didn't see a 200 amp offered on the Napa, Checker, or Autozone websites. Where do I find one?

 

I think that the A/C Generator for your truck is a 95 Amp.
It sounds like the brushes may be getting a little short but if the battery goes down setting then that would not be the Generators fault.
You would then have a drain someplace and would have to track that down.

 

I do not know why you would need a 200amp unless you have a very big radio Amp. and a lot of lights.