Wiring Harness 5 Speed Conversion

[Davismj711]

Hi All,

After 9 years on jack stands my Supra is now financially and time wise ready to be completed. I have purchased a donor 87 turbo 5 speed to do the conversion. Engine is rebuilt, top to bottom.
My plan is to use the 5 speed out of the donor car, my questions after an exhaustive search in these forums without the perfect answer remains incomplete.

1) Is there a difference in the Engine harness from Auto to manual. I have a new engine harness on the Auto trans receiving car, and hope I dont need to use the one out of the donor.

2) Are all of the differences in the body wiring harness ? and should I switch these out ? Or simply use the Auto body harness and cut and splice as I have read in the forums here ?

3) I have both ECU's one poster said that the Auto is detuned a bit, true or not ?

I appreciate all input, and the time necessary to do so. After nine years I want to do this right and not hack up a harness if I dont have to.

Many Thanks to all
Mark

 

[suprastanger507mgte]

You can use the Manual with the Auto tranny ecu/harness.
( auto as a separate ecu anyways located in the kick panel)

The ecu plugs/body harness both are different for Pre 89( yellow plugs) and post 89 cars. (grey plugs).

I don't think the cars are detuned.

 

[Davismj711]

You can use the Manual with the Auto tranny ecu/harness.
( auto as a separate ecu anyways located in the kick panel)

The ecu plugs/body harness both are different for Pre 89( yellow plugs) and post 89 cars. (grey plugs).

I don't think the cars are detuned.

Thanks for the fast reply ^^

Both cars are 87's and yellow plug ECU's.
My question is, should I swap the body wiring harness, and use the 5 speed ecu .

OR

Use the Auto ECU and body wiring harness and cut and splice the clutch sensor, and reverse lights ?

 

[suprastanger507mgte]

Thanks for the fast reply ^^

Both cars are 87's and yellow plug ECU's.
My question is, should I swap the body wiring harness, and use the 5 speed ecu .

OR

Use the Auto ECU and body wiring harness and cut and splice the clutch sensor, and reverse lights ?

I think if you want least amount of work, go with the second option since the years are the same.
the clutch bypass should be failry easy to do compared to pulling the dash, replacing the harness etc.

 

[xXSupramanXx]

i do believe that if u use the auto engine harness it will have to be modified to work with the manual tranny

 

[annoyingrob]

wait, youre Supra has been off the road for NINE YEARS?

 

[Davismj711]

wait, youre Supra has been off the road for NINE YEARS?

Yes indeed it has. Many contributing factors, 2 sons in college to name 2.:1zhelp:
But concerning this swap, im torn between R&R of body harness and simply splicing wires where needed on the exsiting Automatic body harness ^^