I chose to lay the GM transmission and DS O2 sensor harness parallel to the Toyota transfer case wiring.. for which toyota installed a large waterproof plug. I could have eliminated this and spliced/soldered everything but there is plenty of room, any splice/solder might not be quite as durable as factory toyota, and this connector is well waterproofed. So it stayed. Also visible is my joining of the oil pressure sender circuits. The gray/purple one is GM, the black and white ones and plastic box (diode) are for the toyota sender. I basically just copied the shielded setup toyota used with some shielded wire out of the toyota harness. This will run along the MAF wiring then drop down to the area of the AC comp clutch wiring and ED1 connector into the toyota front clip harness.
One important note about the transfer wiring.. in stripping the unused toyota transmission wiring a couple ground wires are eliminated, and these are necessary for some of the transfer case functions. Make sure you find a ground for these. The GM harness happened to have the wires I needed, but they'd be easy to overlook and whether those wires are so easily available is highly dependent upon each individual wiring setup
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ECM end. Pink wires go to the (now wired) new fuse block. Coiled stuff is for throttle/BCM/GMLAN. Gray round connector is my primary method of integrating tach/power/MIL into the factory front clip harness and fuse block. There is now another connector with large gauge wire parallel to the round gray one. I'll get more pictures but I decided to use the factory toyota block for the 2 relays I needed.. fuel pump and pwr trn. The old EFI Main relay (and fuse) is now fuel pump, triggered by one of the circuits in the round connector. In addition I added a relay exactly like the EFI Main to a blank spot in the box for Pwr Trn. This higher-current circuit goes through the other connector I mentioned then to the fuse block wired into all of the pink wires.
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One (IMO) clever thing I did is repurpose existing wires in the toyota harness. For instance.. the black/red wire on AM1 from the ignition switch goes through the body harness into the front clip harness via EA2 connector.. then on to the coil. I don't need that coil wire anymore. Now it is the Ign switched +12v for the Gm ECM and TCM. Each of those circuits needed fuses.. so they were added to the toyota block. This used up all of the available fuse space in the toyota box, so I did the rest of the fusing in a waterproof block made by littelfuse. More details on that later.
The toyota Red and red/yellow wires from the toyota EFI Main relay take a similar path to the area of the toyota ECM. One is now a tach signal.. which will get joined (through a SGI-8 to make up for 8-cylinders) with the stock tach wire from the toyota ECM to the cluster. The other is now the MIL. This minimizes the number of wires that need to be added to the engine harness across the engine bay, and reduces required trickery at IH1/2.
The white/black wire that went from the toyota ignitor to the coil isn't used.. so it is now moved to take +12v from what is now the fuel pump relay in the stock toyota block, through EA2, where it was joined with the red/black full-voltage wire under the DS hood strut to the stock toyota fuel-pump relay.
Hopefully when I get the BCM in I'll be able to run the alternator on two wires from the ECM.. if that's the case I pick up a few more potential circuits through EA2 that aren't used (and a spot in the block) for other accessories to be added without running new wires all over the place.
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Said round connector is what came off the toyota cruise control module. Fully waterproofed.
The seven wires are as follows:
+12v IGN to ECM
+12v IGN to TCM
+12v constant to 2 circuits in secondary fuse block for ECM/TCM memory
MIL
Tach
ECM trigger for PwrTrn relay
ECM trigger for fuel pump relay
The other connector with much larger pins not shown brings +12v from PwrTrn relay to the secondary fuse block for all of the engine electronics (injectors/maf/etc)
I'll try to get pics of the modified toyota and secondary fuse blocks tomorrow
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Edit: Also, while I'm not using electric fans the trigger wires are there for them. They'd be too high-current to use the toyota or small waterproof box I got, so I have a plan for them too.. the old ABS power wires provide a convenient 60A fuse in the toyota block.. all of this is IF I end up going that way. I hope to not need them.