Anyone have a good diagram on the power source and feed to the ignition for an 88 4 cyl. My truck does not have a underhood fuse box. Just a single 6 gauge wire going into a 5 wire splitter and 5 fuseable link wires coming out.

 

The factory service manual, section 8W.

Since it's a total of 107 pages long, it may be better to just pick the darn thing up off Ebay.

Currently I can find them for starting at $25.

If you'd rather not have paper, you can find the wiring diagrams at AllDataDIY.COM and at EAutoRepair.COM (the first is AllDATA, the second one Mitchell 1, both for DIY users).

SOMETIMES you can find the PDF on Ebay also.

But yah, what you're looking for is in there, along with the V6 specific stuff also.

RwP

 

I already have that saved on my phone, and had already parused over it. The exact information I am looking for isn't really detailed in the diagrams, or someone has hacked my truck up that badly from original. I'm installing a stripped down 5.9 magnum harness and want to clean up all the unneeded wire mess from under my hood. Didn't really want to have to DVOM everything to trace down it's power source. I got enough from the PDF on here to get the harness hooked up to my ignition, so I guess that will get me by for now.

 

When I did my Magnum swap into my '89 I used a Magnum harness which I had to make a few mods to, but I left in stuff I didn't need. A couple things I remember: The fuel pump and sending unit wires were in the Magnum harness' firewall connector (the big bulkhead connector). I had to remove those and run them to my '89's chassis harness because that's the route the '89 wiring took to the fuel tank, not through the cab like the Magnums. I also had to extend a few of the Magnum engine harness connectors to reach their new destination in my '89 engine bay.

Have thought about making a clean harness from scratch, using only what's needed for my injected engine and the accessories I have. There's a lot of wiring for things I don't need. Was just thinking it might be helpful to others if you could post your "minumal" harness particulars, once you have it down.

 

I bought a reworked harness that for a 'hotrod", so essentially engine management only for the tlengine and ecu. My truck was already stripped to bare bones before I got it and it was a 4cyl 5 speed fleet truck, and had a 318/727 with GM HEI distributor installed and mechanical fuel pump. Everything works so far, but I should be firing it up tonight after work and will have a better idea what is or isn't working.