87 Supra Wiring Harness

slader99 · 04-21-2008, 06:21 AM

Hey all,

Need some help on the old 7mgte wiring harness... Spun a rod bearing and am now about ready to turn the beast over and I have a section of the wiring harness that I cant figure out....

So the section runs from the main harness towards the tranny... (its a manual) it has the neutral connection, a 4 section rectangular plug, the brown connector for the starter, and 4 wirings going to a double ring lug connection. Two of the wires are brown with black stripes, the other two possibly white with red.... Its about the same length as the brown connection to the starter.

What is this lug for, and where does it go? Thanks for any and all help.... I will try to attach a pic of the connector from the intake manifold down....

Cheers,

Colin Slade

j3pz · 04-21-2008, 03:56 PM

the wires that go to the top of the tranny are for abs unit and the wires that go on the side are for back up lights switch

slader99 · 04-21-2008, 04:25 PM

Thanks, i have no problem with the two longer connectors that pass by the transmission,

I am looking for where the ring lug goes, (theres a picture of the ring above).

Thanks,

cre · 04-21-2008, 05:11 PM

It's a ground. It bolts to an extension coming off the outer flange of the lower intake runner.

slader99 · 04-21-2008, 08:51 PM

Cre,

thanks for the info.... It would probably be a mistake to bolt it to the hot terminal of the start then eh?

Any chance you can tell me where the main engine body ground strap should run from the engine to car body?

Thanks again,

Colin

cre · 04-21-2008, 10:42 PM

OEM ground points are covered here:

MK3 TEWD On-Line

The primary block and ECU ground points are at the intake manifold and the rear right hand side of the head (black wire with yellow stripe).

If you're looking to ground things further a ground strap run directly to the block and to the head from the battery would be good additions. I was surprised to find that my Supra didn't have any significant ground between the battery and block. If yours does I'd like to know.

slader99 · 04-26-2008, 05:49 PM

Just going out to get some rad hoses, then I will be trying to turn it over this afternoon... One lase harness connector Im having issues with. Its off the main harness, leaves the main bundle right between the valve covers at the rear of the engine. Short in length (less than 10").

I provided a pic below. Any suggestions most appreciated!!

cre · 04-26-2008, 08:10 PM

I can't recall for sure, but the first thing that pops into my head is cruise control.

j3pz · 04-27-2008, 11:52 PM

goes to the horn in the corner iirc. its raining so i cant go out and look. pretty confident thats exactly what it is

cre · 04-28-2008, 12:14 AM

BINGO! Theft deterrent horn:

MK3 TEWD On-Line

04-21-2008, 06:21 AM	#1
slader99 Stock Join Date: Apr 2008 Location: canada Posts: 26	87 Supra Wiring Harness Hey all, Need some help on the old 7mgte wiring harness... Spun a rod bearing and am now about ready to turn the beast over and I have a section of the wiring harness that I cant figure out.... So the section runs from the main harness towards the tranny... (its a manual) it has the neutral connection, a 4 section rectangular plug, the brown connector for the starter, and 4 wirings going to a double ring lug connection. Two of the wires are brown with black stripes, the other two possibly white with red.... Its about the same length as the brown connection to the starter. What is this lug for, and where does it go? Thanks for any and all help.... I will try to attach a pic of the connector from the intake manifold down.... Cheers, Colin Slade Attached Thumbnails

04-21-2008, 03:56 PM	#2
j3pz 500whp yet? Join Date: Nov 2005 Location: Mechanicsville, MD, US of A, 20659 Posts: 1,060	the wires that go to the top of the tranny are for abs unit and the wires that go on the side are for back up lights switch __________________ 88 N/A w/ 5spd - stock - not running, bhg 87 turbo/targa w/ 5spd- fidanza light weight flywheel, new oem slave cylinder, apexi air filter, no ac and no heat

04-21-2008, 04:25 PM	#3
slader99 Stock Join Date: Apr 2008 Location: canada Posts: 26	ring connector... Thanks, i have no problem with the two longer connectors that pass by the transmission, I am looking for where the ring lug goes, (theres a picture of the ring above). Thanks,

04-21-2008, 08:51 PM	#5
slader99 Stock Join Date: Apr 2008 Location: canada Posts: 26	thanks Cre, thanks for the info.... It would probably be a mistake to bolt it to the hot terminal of the start then eh? Any chance you can tell me where the main engine body ground strap should run from the engine to car body? Thanks again, Colin

04-26-2008, 05:49 PM	#7
slader99 Stock Join Date: Apr 2008 Location: canada Posts: 26	Just going out to get some rad hoses, then I will be trying to turn it over this afternoon... One lase harness connector Im having issues with. Its off the main harness, leaves the main bundle right between the valve covers at the rear of the engine. Short in length (less than 10"). I provided a pic below. Any suggestions most appreciated!! Attached Thumbnails

04-21-2008, 05:11 PM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	It's a ground. It bolts to an extension coming off the outer flange of the lower intake runner.

04-21-2008, 10:42 PM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	OEM ground points are covered here: MK3 TEWD On-Line The primary block and ECU ground points are at the intake manifold and the rear right hand side of the head (black wire with yellow stripe). If you're looking to ground things further a ground strap run directly to the block and to the head from the battery would be good additions. I was surprised to find that my Supra didn't have any significant ground between the battery and block. If yours does I'd like to know.

04-26-2008, 08:10 PM	#8
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I can't recall for sure, but the first thing that pops into my head is cruise control.

04-27-2008, 11:52 PM	#9
j3pz 500whp yet? Join Date: Nov 2005 Location: Mechanicsville, MD, US of A, 20659 Posts: 1,060	goes to the horn in the corner iirc. its raining so i cant go out and look. pretty confident thats exactly what it is __________________ 88 N/A w/ 5spd - stock - not running, bhg 87 turbo/targa w/ 5spd- fidanza light weight flywheel, new oem slave cylinder, apexi air filter, no ac and no heat

04-28-2008, 12:14 AM	#10
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	BINGO! Theft deterrent horn: MK3 TEWD On-Line

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