Doing a 7mgte swap into my NA and I need to know if an 89 ecu/harness will work with a 91 chassis. I've read that 89 is a shift year as far as electral system goes so will an 89 work on a 91 or do I need my exact year engine wiring harness.
89 ECU/Wiring Harness into 91 chasis?
- Thread starter hcorea
- Start date
It can be done, but it is not a straight swap. The ECU will be fine, but you will need to re-pin some of the body connections on the harness. I went from an 89 to a 92, which is the same as 91. I had to get 5 new harness plugs, and swap around wires from one place to another. If you search my threads (click on my screen name, and search threads, not posts) I had a thread that showed me everything I needed to do. I'd link to it, but I can't figure out how yet with the latest Firefox.
Yes. It can be done, and it is not hard, but I believe I still have a couple of issues with it. I have never gotten my car to run correctly since doing my harness, so I'm not sure of what may be causing the couple of issues I have. If you have access to a 91 harness, I would recommend it.
if you can, find a harness that is the same as the body harness under the dash where it connects to the rest of the car. when i did mine i got a gray plug harness and it was not the same. take pictures of yours and ask to see pictures of the harness you intend on buying. may save you some trouble in the long run.
It is a very common misconception that all grey plugged harnesses are the same. The 89 has it's own. 91 and 92 are the same. And, I am not sure on the 90, if it is the same as 91-92, or if it is different. They went to the air bag in 90, so it for sure is not the same as 89.
Well that could have been my problem. I had to cut and splice my harness to make it work. Like the swap guide says OP, use harness from the same year as your car.
90's are another funky year. Local buds 90 harness is different then my 89's and others 91's. The 86-88 are yellow plugs and 89-92 are grey should be taken with a grain of salt
I'm looking at ordering one from a toyota dealer but i can't find the damn part numbers for the wiring harness itself
Toyota might not even have them anymore.
Pm dr.tweak or pheonixtuning.com and get the number and call.(Idk if i spelled pheonix right.) He can make you a brand new harness with all the right plugs.
Pm dr.tweak or pheonixtuning.com and get the number and call.(Idk if i spelled pheonix right.) He can make you a brand new harness with all the right plugs.
Champion Toyota quoted me $507 for a new one 6-8 months ago. 1-800-327-2087. There was going to be a delay, because it would have to come from Japan, but I don't think it was going to be a real long time. Make sure you tell them what you are doing. They will want to match the harness to your car, but that won't work since it was an N/A car to start.
Thanks for the replies yea i called up my toyota dealer and this is what he showed me-
http://www.cygnusx1.net/Supra/Library/EPC/291420/catalog.aspx?F=8202&P=1
I need to pick which part number the engine wiring harness is but i don't know what the heck this picture means to be honest.
http://www.cygnusx1.net/Supra/Library/EPC/291420/catalog.aspx?F=8202&P=1
I need to pick which part number the engine wiring harness is but i don't know what the heck this picture means to be honest.
87-88 are the same and 100% interchangeable.
89, 90, 91 and 92 all have differences. 91-92 are very similar, 90 is mostly similar to 91-92, but 89 is quite a bit different than all the rest.
Jeff
89, 90, 91 and 92 all have differences. 91-92 are very similar, 90 is mostly similar to 91-92, but 89 is quite a bit different than all the rest.
Jeff
invest in a decent set of crimpers and stirppers. The pins are damn cheap. Lay out the harness on a big piece of cardboard and tape it down so you know the path each wire you remove/splice needs to take. You'll need a coule of flavours of wire and pins. Shouldnt cost more then $200 to nearly rebuild the stock harness. (including a $50 pair of crimps.)
I'm not sure about me doing the wiring I'm defintely not a tech as I said but that's why I'm trying to just buy a harness. One question, will an 89 ECU work with a 91 harness? Any problems with that? Or does the ECU and Harness have to be the same year?
I'm looking at doing something similar to this. I have a 91 turbo with auto, tems, and anti-lock that I am swapping to a 5speed and doing a tems delete. What I can gather in my own research is to go with a same year harness and ecu. To do it right, I am going to be changing the dash cluster and and body and engine harnesses to match the "new" options. ECU will be a standalone. Good luck and let us know how it goes.
You don't need to switch the body harness or anything if you have a 91 turbo. Everything is set just change your ecu and engine harness along with tranny i believe..
Ya you can use auto ecu with 5 speed. Just hide the connector for tems and jump the nuetral saftey switch.
hcorea;1640880 said:
Haven't been able to confirm this but I was told by several people (including one Supra-driving Toyota tech) that you can go 5sp-auto without changing the body harness but not the other way around. I don't see how that's possible given the need for the plugs for the auto, but I guess anything could be possible. I know I CAN use the auto harness and jumper the terminals, and I know I CAN hide the tems plugs, but I am going for the "It came from the factory this way" finish and I really am that anal about my car being "done right." Mostly though, I don't want to go hacking, jumping and otherwise screwing with a good harness someone else might be able to use and inviting potential shorts later down the road just to have my reverse lights, abs, etc. in working order. Have heard that an auto-5sp swap never is "right" UNLESS these steps are taken, i.e. always throwing codes or acting funny in some way. Again, this is all just things I have been told by others, so have taken all statements with a grain of salt. If there is anyone who has done this that KNOWS differently, I humbly request and appreciate your input.