I have a 95 f250 7.3 with a zf5, using all the harnesses from a zf5 swapped truck, got it running and driving this weekend and I was driving around the neighborhood testing it out and my tach dropped to zero and the truck died on me, pulled into a side road went to start it back up and noticed no check engine light, hydra not powering up, found the 20 amp maxi fuse #9 blown, swapped it with the trailer brake fuse to try and get it started to drive it home and the fuse blew after turning the key, I’ve been reading up about this and it seems like the issue is normally related to the electronic transmission control, I do have an irate e fuel system and tied my fuel pump key on hot wire in with an empty plug on the transmission harness, idk if it’s related but it’s not the square plug but the round 2 wire plug that I tied into. Any advice or just wiring diagrams of the whole circuit for the #9 fuse would be greatly appreciated

 

Today I started to try and diagnose the issue, using a test light on battery positive and the light on the output side of the fuse with no fuse in, when I turned the key the light came on, meaning if I’m thinking about this correctly the short is active when I turn the key on, first I disconnected the transmission harness plug and my e fuel pump as I had that wired in with the other plug in that harness, light still on when turning the key, pulled the pcm relay and the light wasn’t lit when I turned the key, verified it wasn’t the relay by swapping it with another relay and light still lit so I put the relays back where they were, I disconnected the pcm and my light was no longer lit. To my understanding this either means my pcm is shorted internally, my hydra ribbon cable is shorted to ground, or one of the wires in the pcm plug is shorted to ground, so I then put my test light in every pin and it lit on 4 of the pins, pins 33, 41, 51, and 92, according to a pin out diagram I found online 33 is the vehicle speed sensor ground so the light should’ve been lit, 41 is the ac pressure switch input, 51 is ground so that should be lit, 92 which is the brake on/off switch input. This is as far as I got tonight before running out of daylight. I attached the photos of the pins that lit and the diagrams I was using, I hope these are the right diagrams for my year truck, the trucks a 95 with full 97 wiring harnesses and pcm and idm. Any input would be awesome especially if I’m heading in the wrong direction or missing something completely

 

I used the fuel bowl heater wire for the relay on my Irate setup.

 

Any update on this? I am having the same issue. Tracking down electrical problem is not my strength.

 

yeah I doubt it’s the same issue you’re having though, I’m just an idiot and missed the fact that my wiring harness to my fuel pump wasn’t secured and rubbed on the exhaust manifold melting it, I just fixed the wires and tied the harness up away from the manifold the way I should’ve when I first installed it.

 

**** happens, I left a boost tube loose once on a turbocharged gasser...pipe popped off ha. Now I always hand inspect all aspects of any repair a few times.