Wiring Questions

Apr 4, 2005
I am hoping to get some pictures of underhood wiring, THe Previous owner of our 78 FJ40 with a 350 chevy, did some questionable wiring, and I'm trying to sort it out with the wiring diagram, but there are a few areas I don't know about.
near the battery there is a plug with two back w/yellow stripe wires, one larger than the other, and next to them is another black with yellow stripe that aren't connected to anything I have.
directly above the engine on the firewall are two wires, one yellow and one orange I think. I believe the yellow one is for the water temp sender, but I'm not sure.
For the oil pressure sender I only find one wire that is yellow with a black stripe, and it comes out in the same spot as the wire to trip the starter solenoid.

So far I've rewired the headlights to the factory switch using relay's, and rebuilt the contacts in the ignition switch and rewired it to work, but after taking out 10-12' feet of extra wire and 3 switches, I'm still left with unworking guages, and way to many things hooked to the battery.

My goal is to get the factory guages working, but not sure how much of the wiring was mutilated by the previous owners.


The wires near the battery (assuming it's near the passenger fender in the stock location) are most likely from the stock coil and igniter. If my memory is correct, the two-wire connector (w/2 black/yellow wires, one 10 ga.) would have gone to the stock starter.

The yellow wire is for the water temp and the yellow/black wire is for the oil pressure sending unit. The orange wire probably went to the other temp sensor for the emission control computer.
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