engine harness... pls refresh my memory

[j3pz]

ok ill put my dilema out first. i have an 87t 5sp and just bought a jdm 89+ 7mgte replacement motor. swapped out the sensors so i just need to do the connector swaps on the harness. the harness that came with the 87 was pretty beat up so i bought an 88t 5sp, same harness right? well when i got the harness the connectos going to the ecu are gray, and i know i need a harness with yellow connectors to the ecu.

im wondering if i can still make this harness work with the 87 ecu. i know the hac or whatever is internal for the 89+ ecu and is external for the pre 89's. can i make this harness work? can i swap out the gray connectors for the yellow ones? or do i need to get a new harness? any help will be greatly appreciated

 

[Nick M]

You can always make it work with wiring. Is it worth the extra effort is a different question.

I'm sorry I don't have the EWD's for them handy. That would tell exactly where every connector is, where the wires go, what color they are and expected voltage, ground, or resistance.

If you take up these projects the factory EWD is one of the best tools. Not the pull out at the back of the repair manual. This is a seperate book.

 

[j3pz]

thanks for the reply. ive seen some EWD in the haynes and tsrm and they all seem kind of confusing. ill give them another look. thanks again

 

[shaeff]

ok ill put my dilema out first. i have an 87t 5sp and just bought a jdm 89+ 7mgte replacement motor. swapped out the sensors so i just need to do the connector swaps on the harness. the harness that came with the 87 was pretty beat up so i bought an 88t 5sp, same harness right? well when i got the harness the connectos going to the ecu are gray, and i know i need a harness with yellow connectors to the ecu.

im wondering if i can still make this harness work with the 87 ecu. i know the hac or whatever is internal for the 89+ ecu and is external for the pre 89's. can i make this harness work? can i swap out the gray connectors for the yellow ones? or do i need to get a new harness? any help will be greatly appreciated

if the harness you have has gray connectors, it's NOT an '88 harness. all 86.5-88 harness had yellow connectors, and nothing but.

i started to delve into the changeover when i did my swap, but i gave up about half way through it. it's definately worth just buying another (correct) harness.

get a new harness, and make your life easy. seriously, just sell the one you got, and buy a new one. if someone asked me to wire that up for them, i'd tell them to take a hike...

-shaeff

 

[j3pz]

ok thanks for the advise. the only thing is ive been looking for a harness for the last couple of months, everytime i find one for 87t manual its already sold so im extremely desperate... thanks again

 

[shaeff]

ok thanks for the advise. the only thing is ive been looking for a harness for the last couple of months, everytime i find one for 87t manual its already sold so im extremely desperate... thanks again

if you have a manual, you can use an auto harness. if you have an auto, you cannot use a manual harness.

i have an auto harness in my car. you just leave some connectors untouched. (i'm turbo, 5 speed)

-shaeff

 

[EdgeSupra]

I didnt want to buy a new hanress for my car, but now that I see what a disgusting state its in, i have no problem buying a brand new one from the dealer. and i have the correct harness too, its just that its so badly beaten I dont feel like having a piece of junk supporting a brand new rebuild.

 

[j3pz]

thanks for all the help guys. really appreciate the info. ive decided to use the original harness from the car on the jdm motor. my current issue is im missing a connector on that goes on the driver side of the motor. its near the 2nd knock sensor, grounding wires, a square connector with 3 wires, a clip connect and what im assuming to be the back up light sensor connector and then the bare wires. they are yellow with brown markings and red with a black line. i know one goes to the fuel regualtor but i dont know what the others are for. if this isnt specific enough let me know. thanks for the help again.