I'm looking for a bit of help with the electrical side of my swap. What does the TBI computer need in order to run? I have the whole engine compartment harness from the '88 250 and the engine compartment harness is still in the '93. I was hoping I disconnect all engine related connectors and maintain the '93 harness for the lights, wipers, oil and temp sending units. Then tap the '93 harness to run the '88's TBI computer.

I have printed off the diagrams from Autozone and will go over them tonight. However I can't find a diagram of the bulk head connector for either truck. Does anyone have diagrams for both trucks?

I assume this has been done before but my searches have come up empty handed.

I realize the '88 is a bit of a dog but I have a pristine '93 2wd just sitting there and a rotted out '88 250 4wd.

 

I should also add that this is mainly a plow truck and I have already swapped over the fuel tank, lines, engine, trans, t-case and axles from the '88 250.

 

Think about switching the dash components, computer and everything else the harness connects to (other than lights, since those should be the same)

You might find the solutions to some un-answered questions by looking at the fuse panels for both trucks too...

 

the truck should run if you use the wiring from the 88 under the hood. i am using the wiring from an 87 b250 under the hood of 91 d150.
this is a 93's 50 way disconnect

this is a 87's 50 way disconnect. i could not find one for an 88

 

Thanks this is exactly what I was looking for !

 

Wow, I give you credit for going through all that.

I'd just give up, tear out the wires, and throw a carb intake on that new motor haha

 

It's done. I was able to use the '88 bulk head connecter on the '93 firewall and everything is working great. The only things I had to modify were the high beam indicator wire and temp sender. Now I need to liven up the dog of a motor.