Replace Wiring Harness???

joshtexican · 06-02-2010, 11:11 PM

Hey guys,

I threw a rod in my 86.5 na. I have a built 7mgte motor on an engine stand that I was going to eventually put in another supra (turbo body). So I am forced to put the 7mgte into my 86.5 mk3. I have the complete uncut harness, ecu, and motor (still putting together) for a 90 model 7mgte.

Question: would it be easier to pull the complete wiring harness out of NA and replace it with the complete wiring harness for the 90 7mgte?? If that were the case, do I need to use the dash as well or is it basically just swapping the harness, ecu, and motor?? - VS - Splicing the NA harness and doing the necessary wire work to make it work the 90 7mgte??

I am in desperate mode to get this car running already and now I am basically forced to put this motor together and drop in the car. I was putting this motor together little by little but now I am making it my priority to drop in my car.

I will start taking the car apart this weekend and any help will be appreciated!! I am waiting on the gasket kit to get here and a few other things I ordered. Hope to hear from some of you more experienced mk3 owners.

Thanks in advance

wstanek · 06-02-2010, 11:27 PM

just replace the whole harness would prolly be easier

joshtexican · 06-03-2010, 12:09 AM

That seems to be the best way. Just wondering if anyone has ever done this on a 86.5 before.

wstanek · 06-03-2010, 12:29 AM

Not me but i assume many people have on this forum look around theres gotta be a post cuz there is hundreds of posts in this area alone!

btwilson86 · 06-03-2010, 01:52 AM

I believe that in addition to replacing the engine harness, you will want to replace your dash wiring harness and gauge cluster from a Turbo vehicle as well. There are some compatibility issues with some of the gauges (I believe the Tach is one of them)

joshtexican · 06-03-2010, 02:15 AM

Ok cool, I do have 2 dash wiring harnesses and 2 gauge clusters. So just swap everything correct?

06-02-2010, 11:11 PM	#1
joshtexican 3" Exhaust Join Date: Apr 2010 Location: NC Posts: 136	Replace Wiring Harness??? Hey guys, I threw a rod in my 86.5 na. I have a built 7mgte motor on an engine stand that I was going to eventually put in another supra (turbo body). So I am forced to put the 7mgte into my 86.5 mk3. I have the complete uncut harness, ecu, and motor (still putting together) for a 90 model 7mgte. Question: would it be easier to pull the complete wiring harness out of NA and replace it with the complete wiring harness for the 90 7mgte?? If that were the case, do I need to use the dash as well or is it basically just swapping the harness, ecu, and motor?? - VS - Splicing the NA harness and doing the necessary wire work to make it work the 90 7mgte?? I am in desperate mode to get this car running already and now I am basically forced to put this motor together and drop in the car. I was putting this motor together little by little but now I am making it my priority to drop in my car. I will start taking the car apart this weekend and any help will be appreciated!! I am waiting on the gasket kit to get here and a few other things I ordered. Hope to hear from some of you more experienced mk3 owners. Thanks in advance

06-03-2010, 01:52 AM	#5
btwilson86 Super Moderator Join Date: May 2007 Location: Billings, Montana Posts: 1,034	I believe that in addition to replacing the engine harness, you will want to replace your dash wiring harness and gauge cluster from a Turbo vehicle as well. There are some compatibility issues with some of the gauges (I believe the Tach is one of them) __________________ 1989 7MGTE R154 Targa Top White Package w/Blue Interior Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels

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06-02-2010, 11:27 PM	#2
wstanek 3" Exhaust Join Date: Apr 2010 Location: Stoney Creek Posts: 178	just replace the whole harness would prolly be easier

06-03-2010, 12:09 AM	#3
joshtexican 3" Exhaust Join Date: Apr 2010 Location: NC Posts: 136	That seems to be the best way. Just wondering if anyone has ever done this on a 86.5 before.

06-03-2010, 12:29 AM	#4
wstanek 3" Exhaust Join Date: Apr 2010 Location: Stoney Creek Posts: 178	Not me but i assume many people have on this forum look around theres gotta be a post cuz there is hundreds of posts in this area alone!

06-03-2010, 02:15 AM	#6
joshtexican 3" Exhaust Join Date: Apr 2010 Location: NC Posts: 136	Ok cool, I do have 2 dash wiring harnesses and 2 gauge clusters. So just swap everything correct?