Wiring harness questions

[TaylorRacing]

So i've searched but i have yet to find the answers i need. I have been in the process of getting my swap finished up and have run into a problem. I've been under the impression that my motor was an 87. Now reviewing my receipts the this morning. It says my motor is out of an 89. So, with this new information i'm frustrated i someone how made this mistake. Now i have already gone through an entire yellow plug ecu, fix any or all connectors with solder and heat shrink and lumed the whole harness. So what i'm trying to say is, am i able to run this harness and ecu or should i sell everything and find a grey plug harness? I have also verified the block differences and it is the heavier block with extra ribs on it.

So any and all input is appreciated. Whats the best way to go about this?


-Mike

 

[Dan_Gyoba]

I have an '87 yellow plug engine harness connected and running fine in my '89 chassis.

I can als0 confirm that the '89 harness is grey plug. If the harness that you have is yellow plug, it'll be fine in your '87, even if it is from an '89. As a bonus, if the block is from an '89, it should be the newer, stronger block casting, but still have the 6M (higher revving) crank as expected by an '87 ECU.

Basically, I think that you'll be fine proceeding as planned with what you have.

 

[Jeff Lange]

What year is your car?

As long as you have a harness/accessories that match the year of your car, it doesn't matter what year the engine itself came from. If you have a yellow-connector harness, it is from 87-88, and if you have an 86-88 car, it is what you want to have. If you have a grey-connector harness it could be from 89-92, you'd need to check other connectors/part number to verify what year it came from. If you have an 89 car, I'd highly suggest getting an 89 harness. If you have a 90-92 car, any year can work relatively easily, but there were still differences between those years that will need to be taken care of.

The only years that are entirely interchangeable are 86-88, everything after that was different year to year. All 86-88 harnesses are yellow-plug, all 89-92 harnesses are grey-plug.

Jeff

 

[TaylorRacing]

just so i'm clear because i've been kicking my self all day. The swap is in a truck so as far as the harness working into any factory dash isn't necessary. i just need to verify the yellow plug harness will work fine with an 89 motor. If this is true i will be stoked!


-Mike

 

[Jeff Lange]

What year is your car? Or is this even going into a Supra?

As long as you have a harness/accessories that match the year of your car, it doesn't matter what year the engine itself came from. If you have a yellow-connector harness, it is from 87-88, and if you have an 86-88 car, it is what you want to have. If you have a grey-connector harness it could be from 89-92, you'd need to check other connectors/part number to verify what year it came from. If you have an 89 car, I'd highly suggest getting an 89 harness. If you have a 90-92 car, any year can work relatively easily, but there were still differences between those years that will need to be taken care of.

The only years that are entirely interchangeable are 86-88, everything after that was different year to year. All 86-88 harnesses are yellow-plug, all 89-92 harnesses are grey-plug. That being said, any of these harnesses will work with any year engine, you just need the matching ECU/sensors. If you have a complete yellow-plug harness, ECU, etc. it seriously makes no difference what year the engine is from.

I recently helped do an 87 7M-GTE engine and R154 into a 91 N/A Auto car with a proper 91 engine harness and aside from swapping a few coolant sensors from the 7M-GE engine, and changing one single wire on the dash harness, everything connected and hooked up like it was made that way from the factory.

Jeff

 

[Halsupramk3]

the only difference between a pre 89 engine and a 89+ engine for sensors is on the Tstat neck. i think the ecu temp sensor is different. either that or the temp gauge sensor. so if you have a 87-88 harness put the tstat housing for a 87-88 engine. if 89+ harness use the tstat sensors from a 89+ engine. that is the only difference for engine sensors. you can just switch the sensors on the thermostat neck.

87-88 harnesess are same. 89 is a unique year. some i think are yellow and some are grey. 89 harness have a different body plug than 90+. the 90 to 92 harnesses are the same except the 02 sensor plug. i think the 90-92 engine harness body plugs are the same.

hal

 

[hvyman]

Knock sensor plugs and o2 sensor plugs are different as well.

Engine year doesn't matter for harness year. Any engine will work with any harness with the right plugs on the sensors for the harness