7mgte engine wiring questions

[83restomod]

i also made this thread on cs.com but maybe some of you guys can help me out. pretty much just wondering where these plugs go and what they are. remember this in in an 83' supra so ignore the plugs that are on the body. thanks


1983 supra--->89' 7mgte swap

there are going to be alot of questions here. i have no idea where any of these plug/wires go. it seems like there are alot of wires that dont get used but im not sure.

i have the engine harness in the car an pretty much pluged in. one of Shawn's sub harness is pluged in by the fuse box (that was the most simple wiring job ever!!! thanks shawn) but as i stated above there seems to be alot of plugs that are not used? not sure. thanks

these cluster of plugs are by the fuse box. they are mk2 body harness. below is the break down.

the yellow plug and the white plug, plug into this harness below but the other end of this harness seems to go to nothing on the car? so what do i do with them or am i missing something? below is the harness that plugs into the yellow and white plug.

also these are a branch of plugs that come from the 7m engine harness and brach off at the begining of where the injector plugs start near the fire wall. they then go down through the intake and towards the driver side engine mount. no idea what they go to. there is nothing there. maybe emmissions stuff? im not running any so maybe thats it?

and the last set is these. they branch off by the throttle body of the 7m harness. there is nothing near them to plug into. any ideas?

and these last 2 pics are of a plug on the 7m harness near ECU. any idea what this is and what year harness it is from. my old 89' had a different plug, same color in its place. thanks

 

[gtsfirefighter]

Pictures 4 5 6 7 are plugs for an automatic transmission. The small brown rectangular plug is the starter signal wire. It plugs into the bottom of the starter.

 

[83restomod]

damn. i was told it was a 5 speed harness i was buying from a member on here. can you run a auto harness without issues on a 5 speed? i have a manual ecu that is matched to the motor. story goes like this. i baught a 89 turbo car. took motor and trans out swaped it into my 83. the harness was no good. so i baught another harness off a member on here thinking it was a 89 manual. i think he sold me a 90' auto.

 

[Supra-Kid315]

Its a auto harness but it shouldn"t be a issue i just did a 7mgte and 5spd swap into my 89 NA and i connected 2 wires from one the transmission plugs (has 3 wires) but you also need the other end of that connection (comes from the tranny) you can go to the junkyard and take one off from a junk supra using your five finger discount :sarcasm:. and there is a thread on that to i believe u connect the black and white wires together but don"t quote me on that i will look for that thread for you and post it.

 

[Supra-Kid315]

also the 8th and 9th picture the black plug i think is your cold start injector plug (plugs to the cold start injector behind the intake manifold kind of underneath) and the 2 single wire plugs are the knock sensor plugs and i dont know about the red plug

 

[gtsfirefighter]

damn. i was told it was a 5 speed harness i was buying from a member on here. can you run a auto harness without issues on a 5 speed? i have a manual ecu that is matched to the motor. story goes like this. i baught a 89 turbo car. took motor and trans out swaped it into my 83. the harness was no good. so i baught another harness off a member on here thinking it was a 89 manual. i think he sold me a 90' auto.

Don't worry, it's no big deal. Many people are running an auto harness on a manual car.

also the 8th and 9th picture the black plug i think is your cold start injector plug (plugs to the cold start injector behind the intake manifold kind of underneath) and the 2 single wire plugs are the knock sensor plugs and i dont know about the red plug

Yes, the grey ones are knock sensors and the black cold start injector. I'm thinking the red one is for a VSV that goes under the intake. It's emissions and if you took all that off then you won't have nothing to plug it into. You'll need to feed the knock sensor plugs down through the intake as the sensors are way up under there. These should have been plugged in while the engine was out. One knock sensor is right by the starter and it could be difficult getting the plug on since they are so close. It was for me anyway.
BTW, your harness looks to be in great condition. The plugs are so clean and unbroken.

 

[83restomod]

yeah the harness is ok. i cleaned it up some more and just had to replace a few connectors that were not up to my standerds. no big deal. i would of rather had a 5 speed just cause there is less crap on them. i dont like messy wires. i can work on my engine and have clean hands. call it anel but i like clean. thanks for everyones help. i got all the plugs squared away. also i dont need to mess with the auto stuff cause the car is a 83 and also the starter wires just get left alone. ill tuck them or zip tie them nicly away. again thanks for everyones help. one step further


does anyone know what the plug in the last 2 pics is? that one has me confused. its not on my old 89' harness and it only has 3 wires. the plug thats in its place on the 89' harness has more than that. any idea?

 

[zachm611]

edit: someone already answered.

 

[ABQMK2]

Im running an auto harness on my 7mgte swapped MK2...you dont need to do anything with the auto tranny plug portion of the harness....MK3's have a an extra ecu/computer for theirs.....we dont...some people say you need the NSS neutral start switch...I have one siting on the bench if you think you need it I didnt.

 

[SupraRacer]

i had an auto harness on my 5spd 7m car. basically all you need to do is lookup which two wires go to the neutral start switch cut them before the plug and splice them together.

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=D&P=32
there is the page you need. looks to be a black/white that you splice in with a black/blue wire. but id double check.

That little wire in the last few pics is a dash harness wire, idk if you need it on your mk2