jrobb913

hey guys, i have a 1989 Toyota pickup with the 3.0 V6, my engine recently blew so im replacing it with an exact same engine, i wanted it all plug and play with now issues, here is my problem:

the wiring that runs into the fire wall from the engine has 5 plugs total, 3 plug into the ecm or ecu what ever you'd like to call it, and the other 2 plug into the cab, the 2 that plug into the cab are different from the two from the old engine, i looked it over and most of the wires are the same but there's still some stragglers that would be left unhooked if i were to wire in the old plug. what should i do?

Plug #1: old engine - 15 wires total
new engine - 12 wires total

only 8 of the wires match up from plug to plug

Plug #2: old engine - 13 wires total
new engine - 15 wires total

only 10 wires match up from plug to plug

any help would be greatly appreicated

jrobb913

nobody can help me with this wiring? engines out of a 1994 and mines a 1989...

SacRunner

Have you pulled down the wiring diagrams for the 2 motors from https://techinfo.toyota.com/ ?

Is one a manual the other an automatic?

Have you considered swapping your wiring harness onto the 94?

Keep in mind that while you're dealing with the same motor, the applications are completely different and as such all the "extras" will be different. Extras = transmission connections (M/T vs A/T), speedometer connections (mechanical vs electric), ABS, cruise control, emissions equipment.

Your absolute best bet, is to use the 94 as a long block and transfer as much of the good parts from your 89 over as you can.

jrobb913

i tried looking up wiring but i dont know where to look or what to search for, they were both standard and honestly, every bolt on my engine is stripped from the previous owner, i was going to swap the wiring harness but half of the stuff is totally different wiring and everything from engine to engine, they were both pretty basic so options wise, both were mechanical speedo cables, no abs or cruise or anything really, every plug on that engine matched my old engine except the 2 that run to the cab

SacRunner

There's a basic video tutorial on the TIS site in regards to how to navigate their site, watch that. Then go and download all the EWD (Electrical Wiring Diagram) PDFs for your application and the 94 donor motor's application.

You'll need to identify what those 2 extra connections are, and what each of the wires inside them are. Then you get to make the decision whether they are needed with your 89 or not.

(The TIS site may not have much for the 89, but go browse around the 3.4 swap forum, there's a lot of info for the 87-89 3.0 wiring scattered around in there).

That will make things a lot easier.

I'm pretty sure the alternator plug will be different, but that's nowhere near "half of the stuff," what else if different? Have you considered "Frankenstein-ing" your 89 harness to work with the 94 motor (cut the ends off that are different and solder the 94 ends onto the 89 harness)? although, unless you REALLY know what you're doing (i.e. have the 2 sets of EWDs and traced every wire) I wouldn't recommend this one.

As you know, you have some work to do to make the two systems work with each other, the real question you have to ask yourself is whether you'd rather do mechanical (use the 94 as a long block and swap over all the 89 parts you can) or electrical (track down the 2 EWDs find the differences and match up all the wires and correct connectors) work.

I'm basing all this off my on-going experience swapping a 96 3.4 (from an A/T) into my 91 that had a 3.0 (will be staying M/T).