Dash harness out and unwrapped
Culprit wire (Upper left corner/Butt connected)
So starting from the beginning the fuse blew randomly driving down the road I lost all gauge functions, alternator stopped charging all the good stuff. But long story short I spent a weekend and pulled the ENTIRE dash harness and unwrapped it to find a possible short. But to no avail, so during reinstallation I plugged each connector 1 by 1 until I found the culprit, an 8 pin connector that is located by the ECM and runs under the hood. Additionally I found the wire that was causing the short, cut it, and then plugged the connector back in. Everything works this way the only problem is the engine will start and run without this wire, but will die after 3-5 seconds no matter what I do. My question to you guys is... What does this wire run? So hopefully I can work from the component backwards to find the short.

 

Looks like a red wire but hard to tell exactly If has any stripe at all.
If red, it supplies ECT computer that could cause truck to shut down if not supplied power
Other parts it supplies:
PPS (Don't know what that means)
Power window relay
Alternator Excitation (IG)
O/D off indicator
Neutral Safety switch and/or Backup switch - These two are my primary suspects for short that blows the engine fuse.. The harness could vibrate, rub against the tranny and wear out insulation (In This Post).
OR the switches themselves could short to ground.

 

It's a manual trans, after work today I'll take a look at the backup switch see if I can work from there and the wire has no stripe just red with little black marks every inch or so.

 

You sir are a genius!!!! That was exactly it! The fuel cut solenoid when out at the same time.... So I've since fixed both problems and I have the yota back!!! Thank you sir!!

 

ray is really excellent for electrical advice/knowledge/troubleshooting. that said, what, exactly, solved your issue? pointing it out may help someone else. ie, was it the backup switch?

 

Yes, O.P., what exactly did you find out? Mind sharing pics so others may learn WITH us?

 

Sure thing, sorry for the LATE reply but it was the red wire going into the backup switch on the LH side of the tranny. There is a little metal clip that holds the wire to the trans and that is exactly where the wire was rubbing!

 

Thanks for posting what the problem was!

It is always nice to hear back from the Thread Starter, no matter if it is late or not!

 

Yup, Toyota parts are bullet-proof...

To those reworking that part of the harness, I suggest you consider:
1) converting that backup switch control to "switched-ground"; use the switch to provide ground to relay negative. Use relay to power the stock backup ligts AND more, AND
2) Get that backup and 4WD switch wires and the starter solenoid control wire out of the harness under / near the intake manifold to make it less crowded there.

Second that.

 

OP I really Hope you had another reason for pulling the dash Harness out.

Check the simple things first

Then doing electrical work without the Electrical Wiring Diagrams is like driving blind folded

 

I didn't It was a process for sure... And I learned a lot haha.