5.8 efi swap

[brentmc]

I've searched with little results. I'm looking for the pin out for the ecm and big round firewall plug on a 89 f250 5.8. I have the whole setup from the donor truck(wires, manifolds, ect) but it has all the wrong hard shell connectors for it to fit my 94 ranger 4.0 V6. I'm thinking of just re-pinning the firewall plug to save me from having some spaghetti wiring.

 

[SenorNoob]

You'll probably have to just start matching circuits and comparing them.

Why do you need the ECM pinout? Can't it just be plugged into the matching harness from the donor?

 

[Elutheros]

I'm a little confused by your post. The 4.0 plugs never will just connect to the V8 harness. The round firewall connector contains about 10 wires you must splice into the V8 harness to make things work, so re-pinning that whole plug seems to be a waste of time. If you have the complete harness from the donor then your best bet is to figure out which wires from connector 105 (the firewall connector) need to be spliced. The 4.0 engine and ECM harness will be removed during the process. The EVTM for the 89 F250 and the 94 Ranger will answer all the connection questions and the Harwood conversion manual is worth the $25 even if it has a few differences due to using a Mustang harness.

 

[brentmc]

Wiring isn't my strong suit. Plus I thought the ecm was in the passenger side of the cab, but as it turns out it's in the same location of the 89's harness. I can't seem to find any info on line about the round plug. Like I said wiring never been something that I've been really good at. I never heard of the Harwood conversion manual but I'll definitely be looking into it.