I have just replaced my old 3.4l with a new one. Now after going through all fuses and the entire wiring harness multiple times, my tachometer speedometer temp gauge, alternator, start cancel button, windows or fan for ac or heat won't work. I have looked through wiring harness diagrams. If someone could point me on the right direction I would greatly be appreciative. And I have redone all the engine grounds.

 

Auto or manual? What yr is the replacement? Assuming its from a 4x4 just like yours.

 

Manual, the engine was pulled from an 00 Tacoma. All wiring harnesses hooked up and the engine runs great when I have a freshly charged battery hooked up. No check engine light but the battery light does come up in the dash

 

Just which engine harness and ECM did you use??

That might be the start of the problems.

Big difference between the 2 years .

Some plugs are the same but the pins are different

 

I had used the exact same harness that was on my original 3.4. Same ecm. The engine runs perfect as I was saying. I compared all sensor plugs to the original engine and the wires were the same colors.

 

i had to use my original harness bc the donor engine came from an automatic. I used original alternator, powered steering pump and ac compressor. My original transmission and transfer case.