alternator

[burnitdown11]

Ok i am having such a frustrating couple of days with this thing. The other night when i was driving home my alternator took a dump on me. So I replaced the alternator and when i hooked it up it shorted out again. so i had the alternator and battery tested both were bad. So i bought new battery and exchanged the alternator just for the alternator to go bad yet again. I have looked for bad grounds burned wires i can not figure out what is causing this and i need it fixed. BTW can the computer have anything to do with it. O sorry by the way it is a 97 f150 4.2 liter engine

[DeltaP]

Any other recent work done to the truck? Any recent collision damage? Any add on's? Boat trailer still hooked up to it ? Any off roading? Double and triple check wiring and cables. Make sure polarity is correct. Doubt the computer could cause this but this could affect the computer.

[burnitdown11]

No no tow package of any sort and no offroading. Put KC lights underbody neons and a stereo system in recently but have unhooked all of that with the same end result.

[DeltaP]

Take no wiring for granted. I'd especially check the cables going to the fender relay and down to the starter. I hope yer running those accys through a relay circuit and dedicated fuse.
Oh yeah, if that stereo system includes subs then theres some more serious cables and routing that needs to be checked.

[burnitdown11]

well the stereo system is on a cap and dedicated fuse the neons and kc lights are on their own relays and even with all of that unhooked the alternator still shorted out

[DeltaP]

Make sure you haven't pinched the alt B+ wire to the alternator between the mounting brackets and the ring terminal isn't shorting to the case. I suggest you dont go on wire appearance alone. Move each wire physically to make sure it didnt melt to something or wires melted together.