Wiring harness help please

[Greased-lightning]

So I got a harness from best I can tell a 93-95 c1500 I have some connections I can't sort out posting pics please chime in with what you think the connections are thank you

[fastacton]

The connector in 1&2 is probably where the engine harness interfaces with the dash harness. Most of those wires won't be needed, but you'll probably have your ALDL connector, VSS and power wires (and a couple of others) there, you'll figure those out as you're stripping down the harness. I normally cut that connector off before pulling the harness.

The connector in #3 is your oil pressure switch/gauge connector. I delete that on my harnesses.

#4 looks like the wiper motor, you'll delete that as well.

It looks like the fuel pump relay is there, so that should be a '93 or '94 harness. They're easier to rework than the '95, but can't be used with the '95 4L60E without adding a wire to the transmission connector.

[Greased-lightning]

Thanks so much I have went round and round with that thing.. The oil pressure plug how do I bypass that?
Also the grey wire coming off the 20 amp fuse do I run that back to my + terminal on my inline pump? And ground off the - pump post the frame?

I also identified my knock sensor but no signal moduel plug near it, but I did find one near the fuse box block that's confusing me the knock sensor module I bought only has 5 prongs and the harness plug has 6. Any ideas?

[fastacton]

Which ECM did this come with or what color are the ECM connectors? You won't have an ESC (knock filter) on most '93-95 systems unless it had a manual transmission because they built the knock filter into the MEMCAL (chip). The plug in the pictures was probably the ABS connector and isn't part of the TBI system.

For the oil pressure connector, just follow the wires to where they splice into the rest of the harness and cut them there (it will be close to the fuel pump relay).

On the fuse wires, one should be going to the relay and oil pressure connector, and the other will go to the ECM and fuel pump.

[Greased-lightning]

Ecm is a 93-95 7427. Thanks for the info you have probably saved me several hours

[Greased-lightning]

So the grey wire going to fuse/Ecu is the hot wire that goes to the pump right?

[Greased-lightning]

One more question I had to splice in a missing data port connector and I have 1 wire I can't figure out fuel pump test 12v. Does that splice into the grey signal wire?

Thanks again for for all the help

[fastacton]

Yes, that gray should have one leg that ends near where the firewall connector was on the driver side. If you got enough of the harness, it will end in a 2 pin weatherpack connector which would provide both power and ground to the pump.

You don't need to run the fuel pump prime wire to the data port, the only ones that are required are the two that go to the ECM (orange/black and white/black) and a ground to pins A, B and M. If you do want to run the fuel pump wire, you'll have to find the red wire coming from the relay and re-route it to the connector.

[Greased-lightning]

Found it thank you

[Greased-lightning]

New mystery, got everything wired up had to delete underhood fuse box it was damaged spliced everything into my current harness. Well first fuel pump didn't work fixed that.. Then no injector pulse fixed. Then the show stopper no spark have 12v to coil and 8 volts to coil when cranking. Worked on it for awhile was checking for codes with my laptop when I heard a hissing noise and saw smoke coming out of the coil. It was only receiving 12 volts never seen one do that anyone have any ideas? Going to get the EIM tested today