I am having charging problems in my 88' F250 with a 7.3 IDI. Last week my alternator quit. Neither battery was charging. I got the alternator tested, it was over charging. I replaced both the alternator and the voltage regulator, and still the batteries are not charging. I am thinking something is broken in the wire harness. So before I How do I test the wiring? Has anyone replace with wireharness with a homemade overlay harness?

 

Check the white/yellow wire it is a fusible link.......also the connector is known to go bad. This is the wire that tells the alternator to charge or not.

 

The green wire on the other side of the fusible link was broken. Do I cut the fusible link out and solder the yellow/white, black, and green wires together. Should I put a replaceable fuse connector between the wires? If so, what amp should the fuse be?