Supra Circuit Solutions

Supra Circuit Solutions Small job shop specializing in engine wiring harnesses for MK3 Supras. I also build 7M and JZ swap harnesses for other chassis.

Last day to get a discount!
07/31/2026

Last day to get a discount!

Only a few days left to get your harness build at this discount price. Contact me to get on the list
07/29/2026

Only a few days left to get your harness build at this discount price. Contact me to get on the list

Knock sensor harnesses have been updated. I’ve already sent out a couple and feedback has been great! They now include t...
07/23/2026

Knock sensor harnesses have been updated. I’ve already sent out a couple and feedback has been great! They now include the ground wire all the way to the intake manifold so you no longer have to splice the ground wire under the dash. 100% plug and play no modifications needed. Just swap the pins at the ecu, plug in the knock sensors and install the ground wire are the factory grounding location. With these changes the new pricing will be $125 for GTE kits and $85 for GE kits

Message me to get your harness built! Time is running out for this deal!
07/20/2026

Message me to get your harness built! Time is running out for this deal!

07/09/2026

Reminder to get your orders in this month to save $250 on a new engine harness. Stock or standalone options available. Message me for details.

Happy 250th!! To celebrate, Supra Circuit Solutions will be discounting full harness builds $250. That makes stock repla...
07/06/2026

Happy 250th!! To celebrate, Supra Circuit Solutions will be discounting full harness builds $250. That makes stock replacement harnesses $1550 and stand alone harnesses starting at $1650 including fuel pump wiring. Deal is good till the end of the month. Get on the list now!

Stock harness update: These are the last new diagnostic connectors and AFM connectors that toyota had left in the US. I ...
06/30/2026

Stock harness update: These are the last new diagnostic connectors and AFM connectors that toyota had left in the US. I bought everything they had. If you are thinking about getting an OEM stock replacement harness please message me soon to get on the list. As of now I only have 8 AFM and 10 diagnostic connectors. I am still looking for more but as of now this is it!

Edit: Not for sale individually. These are only for harness builds.

06/08/2026

Contact me to get yours built today schedule is filling fast

New product!!! Knock sensor rewire kits now available. Single wire kits (GE) $65 shipped in the US. Dual wire (GTE) $110...
05/23/2026

New product!!! Knock sensor rewire kits now available. Single wire kits (GE) $65 shipped in the US. Dual wire (GTE) $110 shipped in the US! Install instructions coming soon! Follow the page to keep up to date with new product offerings.

05/20/2026

What electrical products would you like to see for the Mk3? I’m thinking of doing knock sensor rewire kits, fuel pump wiring upgrade kits and possibly engine harness connector kits. Let me know what there is a need for and I will build it!

Address

306 First Street
Peru, IL
61363

Telephone

+18155031123

Website

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