help with vortec and 4l80 swap please

[jamiewilson]

I'll get a pic of it this afternoon
It's about the size of a pack of cigarettes and has a flip up cover on the one side to get to the circuit board. Kinda hard to explain exactly.

[1project2many]

Does this help?

[jamiewilson]

Does this help?

Yes it does and it is the hot fuel mod.
Do you have any other diagrams for the wiring on a 7060?
Or a link to good wire diagrams / gm diagrams online

[dave w]

Yes it does and it is the hot fuel mod.
Do you have any other diagrams for the wiring on a 7060?
Or a link to good wire diagrams / gm diagrams online

I posted a link in Post #7 for wiring schematics.

dave w

[jamiewilson]

That's right, forgot about that link, I couldn't see the pictures of the diagrams on my phone but can on my laptop

[jamiewilson]

got busy doing other things last week getting ready for an ice fishing trip last weekend so didnt get much done last week. but im starting on fixing up the wiring harness today. once i got the 4l80 out and de gunked i figure out that the tranny is a gm reman from 1994 but who ever swaped it did a hack job on the wiring to the tranny plug so gotta get that fixed up first.

[fastacton]

It's possible that hack job was done by the dealer. The 4L80e connector style changed in '93 to cure leakage issues and earlier harnesses were upgraded. I don't know if it was a recall, but most of the earlier vehicles I've seen have been upgraded to the newer connector with varying levels of effort put into the job.

[jamiewilson]

who ever did the wiring for the new plug stripped the wires like 2 inches long then put them in heat shrink crimp connectors but with the wires being stripped so long some were bare and exsposed then a few had holes in the insulation from either a test light or ohm meter. im surprised i was able to drive it for almost 3 years without problems from it with how bad it was wired. gonna try and get the old 7747 harness pulled today then cut the hole bigger in the fire wall and get the new harness ran. should have the tranny and t case in tomorrow

[jamiewilson]

Does this help?

i sapose you have the next page of what the other connectors are easily acceable or know off the top of your head? ie the c200 c235... etc
i think i have a 92 service manual downloaded on my computer just didnt wanna look threw the whole thing to find the page.
since the old 7747 harness only had 1 plug out of the main harness and the 7060 has all them

[jamiewilson]

does anyone have a diagram of the fuse box pass threw connector threw the firewall? both the 87 and 91
most of the wires are the same color just dont know if they are the same functions or not

[jamiewilson]

got the trans in yesterday and everything, still trying to figure out wiring to the fuse box. traced all of them on the 7747 harness but i didnt trace them on the 7060 harness before i taped and wire loomed the harness. only like 3 or 4 wires im not completely sure of were they go/ come from
does any of the wires from the computer go to the fuse box threw the engine compartment on the 7060 harness?

Edit. Broke out the ohm meter and checked continuity and found were the wires run to

[jamiewilson]

So been making some good progress but am getting stumped on two things. Fuel pump isn't turning on and the dash side of the wiring harness. Figured out all but 3 wires from the dash plug a white, red and a black with a white stripe. They run back into the engine compartment as far as I can tell. And I'm not to sure what's going on with the fuel pump. Brand new unit, fuel gauge is workin just no pump
Edit. found a gm wiring diagram finally and looks like the red and white are the injector hot wires and the black/white is for the egr's vaccum system.

[fastacton]

The black with white stripe is probably a ground (maybe even the fuel pump ground?). The red could be the prime wire for the fuel pump, some harnesses had this run through the drivers side and others were passenger side. Not sure about the white one, depends on where it leads to.

For the fuel pump, it's always best to check the basics first. The fuse and relay, then make sure the relay is getting battery power on the orange wire. Check to ensure the 2 pin connector going to the fuel pump is connected and it's gray to gray (or tan) and black/white to black/white. Is the ECM known good? Is it getting both battery power and power from the ignition switch?

[jamiewilson]

The 7060 harness has the injectors hot wires feed threw the firewall at the computer hole then run threw the dash to the fuse box were as the 7747 I replaced had them combined along with another maybe egr at the fuse box. They ram in the engine bay harness to the fuse panel. There is also a big red standalone wire in the computer side of my 7060 harness that I'm not sure we're it runs to but I'm fairly certain that it starts at the junction block. Kinda a pain making the harness work in a different truck. But easier then rep inning and adding the tranny harness.
And the ecm is good since the truck was a running driving truck when I gutted everything out of it.
As for the keyed power to the computer I'm not sure. I took the harness out completely to the fuse block junction from the donor so used the same junction block and everything.
The fuel pump and tank is different too since the truck had dual tanks but I switched it to the suburban tank so I can run tool boxes under the flatbed. So I had to get rid of the tank switch and by pass that. I'm not sure if the electric pumps worked originally in the 87 since the PO had put a edelbrock carb on the motor. So I might have something to fix under the dash.
Along with sort out the old first gen vintage air system wiring In it.
So much wiring for such a simple truck lol

[jamiewilson]

ill post this for future referance and for others to use if need be that is all the wires on the dash harness side from the 91/92 donor truck
white: tach lead.

red : is injector hot wires

purple : is other part of rwal and brake switch also goes to ecm pin a12. i took out the rwal modual and spliced the engine harness direct to the computer then splices the 2 purples remaining into the black connector from dash. ill find out if that works or not. one is from brake switch other is not used since it was with the old t case.

brown: vss input

orange/black: serial data

pink/black: keyed hot and start for brake/tcc switch (splice my red injector wire into)

brown/white: servuce engine light

white/black: diagnostic test

black/white: vss ground

tan/black: aldl F only new wire needed to be ran since 7747 didnt use the F port

gray : wipers

ill post my fuse block wiring once i get that the rest of the way together

that is all from a 1992 gm wiring manual i managed to find on another forum. ill post a link if its alright has alot of different year factory truck manuals