Hi guys. Got a new opportunityfor learning. Had a problem with the alternator not charging on a 99 F150 on Thurs. after much testing and brain scratching, I found a blown alternator fuse (20 amp mini fuse in slot 11 of the fuse panel ) under the hood.Replaced that and everything worked just fine till Fri night when it blew again. Checked as many connections as I can find, but haven't found anything that Ican say was a problem. Any ideas where I might narrow my search?

 

The voltage regulator portion of the alternator is going, going, go.....

Steve

 

For anyone that might be interested, it turns out that the regulator kept testing that it was good, but so did the alternator, and continually blowing the ALT FIELD fuse. Finally, on the third time it was hooked up to the test bench, the output wires were attached, and when the case ground was put on, it arced. So the rebuild shop went through it again, changing out all of the electrics. has worked for a week now and not blown another fuse.

 

Thanks for letting us know what fixed it