86Belle

Doing my first rebuild on my 1986 4x4 Pickup 22-REC. Waiting forever for a few bolts from the Toyota dealership so I decided to clean out the engine bay. While I'm in there cleaning up some really old junk I noticed something that might be a problem when I go to put her back together...

Can anyone help me figure out what the Green wire with black stripe is? It's coming off the wiring harness where the fuel injectors are. I think it's the #1 injector. It's just the loose wire, no clip.

I looked in my FSM, there's an EFI wiring diagram but no mention of this wire. A full wiring diagram might help, did some back searching and couldn't find anything useful. Any ideas?




Not the best picture but you can see where it is on the wiring harness.

RAD4Runner

Coolant Thermo Switch. Double check by taking continuity check to TSW pin of ECU connector.
Switch mounts on top of t-stat housing. Gets its ground through mounting threads so make sure to clean threads on switch and tstat housing and t-stat housing mounting thread and bolts down to bare, shiny metal.
https://www.yotatech.com/forums/f199...l#post52391719

While you're at it, I highly recommend you take all wires that do not absolutely have to be under the intake out of there to clean up the are and make it easier to troubleshoot in the future. Re-route them along inner fender. I think only injector wires absolutely have to be under the intake manifold.


Schematic is of 1988 but TSW wiring is same on 1986 4Runner 4WD.

86Belle

Thanks! I appreciate it. I've had to mess with the wiring harness in the past, it sure is a mess. I got some silicone tape to re-bundle em all up.