Hello Everyone,

I am a new "project" 4Runner owner. Currently doing an engine swap on my 1997 SR5 4x4. I bought a used engine from B&R out of a 99 Tacoma AT 4x2.
My only concern with the engine they sold me was it was not from a 4X4 tacoma, but they said it would not be an issue..
I am finally about to drop the new engine in after hours of rehabbing it and it seems the transfer case harness connections are different. The 99 tacoma is missing the diff lock sensor and both 4wd position sensor connectors?
99 Tacoma Harness - 82121-3G 111C98
97 4Runner harness - 82121 3D390

Can you review my below assessment and confirm im correct in what im seeing? If so i assume my only option is a new harness out of a 4x4? I would re-use my old one but its been cut..

I appreciate any info to help me out here. Thanks.

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99 Tacoma Harness - 82121-3G 111C98
97 4Runner harness - 82121 3D390

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I'd be surprised if that wiring harness even plugged into your ECU let alone all the missing 4X4 stuff.

You'll need to swap out the engine wiring harness from your old bad motor to the donor motor. Everything on the engine side will plug in without any modifications. I was a similar situation, I had a bad 97 engine and swapped in an engine from a 99. The problem was the connectors on the ECM side were all different and the solution was to just reuse the original wiring harness. You'll need to remove the intake manifold to get the injector wires off but it's pretty easy. I want to say it only took me an hour or so to swap the harness over.

EDIT: sorry, i missed the part where you said you cut the original wiring harness. You'll need a wiring harness from a 97 w/4wd. You should be able to find one at a junk yard.

Good luck!

Yup, as others have confirmed, you would have had to swap the harness even if the engine was from a 4x4 Tacoma. There are significant ECU differences between '97 and '99.

-Charlie

Thanks for the confirmation. Just wanted to make sure i knew which direction i needed to go. I have a replacement harness from my same year and 4x4 coming so i can do the swap. I replaced the injectors on the new engine so i should be able to get back in there fairly easily.

Learning as I go!

Thanks!