Recent issue with a no start/no click on a 93 FD. Battery good/ lights and radio work. We already bypassed clutch switch and interlock switch but nothing. Only starts with 12v applied direct from the battery to the black/red wire going to the starter (so the starter at least works). Following the wiring diagram for the theft deterrent and don't see an aftermarket alarm. Anyone with a similar issue or know if another ground might impact no starts?

Searched the threads but most revolve around bypassing clutch switches.

 

The starter circuit is pretty simple. You would probe the ignition switch and work your way down until you find where it stops. Use the wiring diagram and you will find it very easily

 

Wish it were, but tracing a break on 30 year old wiring or the 2D pin on the ecu is proving challenging.

 

Break it down into sections. You're probably looking at it as a whole. Go 1 point to the other point, 1 point at a time. Start at the ignition switch and work your way down. You will find it