1997 F150... I cannot figure out why my battery is not charging. I have replaced the alternator and also have a new starter and wiring harness from the battery to the starter. The small wire on the alternator looks kind of dark and I am wondering if that wire is bad. Does that wire go straight to the battery? I can get a new clip and just run a wire to the positive terminal.

 

Not familiar with your gen truck, but usually that wire you speak of is a ground wire. You can piggyback a larger gauge wire onto it. Flow of electricity will always take the path of least resistance so no worry about hurting anything. Consider upgrading all the grounds/pwr wire from the alt to the battery....and body/frame of the truck (grounds).

 

Check the fuses for your truck. You have a battery saver relay in the dash fuse panel. It is the second down on the left. You also have fuses in the outer pwr box, so you may of blown a fuse. ALSO: the max fuses on the right firewall (2 big). Check those connections.

I'm betting on the relay.

 

It's a intermittent issue. I'm thinking bad connection. I thought the small wire detected voltage and open/closed the circuit to charge the battery.

 

Intermittent-----check the relay in the fuse panel inside the cabin.

 

I swapped the relay with the one on top to see if that's the problem. I'll check it this evening after work.

Thanks