Does anyone have a diagram for what these four plugs run to on the engine side of things? Truck is a 90, engine harness is from an 89, both 302.
I’ve been searching the web and my books and either I’m really overlooking it or I’m not having any luck.
Trying to thin out what I don't need from the harness.

 

I could never find it either, posting so I’ll have it as well if someone has it.

 

I don't have drawings of specific connectors, but here are screenshots of the 1988 Engine/Emissions Diagnostics manual drawings.
The only way I would know to find out, would be to manually trace the wires, based on wire colors. That would probably turn into a can of worms

 

The red Haynes manual groups '87 through '89 together, and '90 through '91 together.

 

I don’t know why, but I prefer how the Pin out is done on the 88 vs 90. I like how they ordered it. Also, difference looks mostly like provisions for E40d in 90. My quick glancing showed everything else in same spots.

Does the truck harness side not have the white plug? I see the other colors on both sides.

 

It has it, it's just under the red plug.

 

Thanks for those.
I'll probably end up chasing the wires anyway. At least there isn't an engine in the way.
The whole project is a can of worms at this point, but I knew that would happen getting into it.


The real challenge is getting the engine in before my shed blows away.

 

To be able to just stand inside the engine bay and go through wiring would be awesome!

 

I understand now, the plugs won't show up on a diagram and I should be matching the wire colors to what is coming out of the EEC instead of looking for them. Simple enough.

Seems to be exactly what you said, just takes my head a bit to catch up I guess.

It's a mess but pretty nice, yeah.
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That section should just be straight plug and play or you looking at replacing/rewiring areas?