I have a 1992 F150 with a 302 that I am having problems with the alternator. I replaced the alternator and the battery and checked all the connections, but it is still not charging properly. I took the alternator to have it tested to be sure it was good and it passed the test. The belt is new and it is not slipping or anything. I am stumped, so if someone can help it would be appreciated.

 

Define not charging properly?

 

The alternator is not putting any power out at all. The truck will only run off of the battery until the battery runs out of power.

 

check ur voltage regulator and your conections

 

Thanks for the suggestions. I figured out what was causing it. I changed out the guage cluster, and the one I had in the truck did not have an amp. idiot light, but the new one did. That was causing it not to allow the alternator to charge, so I had to swap them back out and change only the one guage that was not working. Why that light was messing it up I don't know, but it works now.

 

All clusters that fit your truck have an ALT light, and resistors built in, in case the bulb fails. You probably swapped in a '94-97 cluster, which is wired differently, and isn't a direct swap. For more info, read these captions: