ECU Harness

Topic: ECU Harness (Read 302 times) previous topic - next topic

ECU Harness

January 03, 2026, 06:20:34 PM

Re 1985 2.3 Turbo now in a 1985 Thunderbird.
The car ran good until I tried to secure the ECU better in its support. The only thing it will do now is Idle when cold If I accelerate it dies out and won't start again. I still have spark.
Moving the ECU back to the exposed way it was, I now have two wires with pins on the harness that were not secured into the ECU Plug.
1. Yellow w/ Black stripe.
2. Tan no stripe
If I let it sit overnight it will fire right up and idle.

Re: ECU Harness

Reply #1 – January 03, 2026, 08:07:34 PM

I'm not seeing a YL/BK or TN wire on the diagram for an 85 2.3T ECU. Pic to help ID what location they are?

Re: ECU Harness

Reply #2 – January 03, 2026, 09:06:18 PM

I have looked at all the images of the drawings I have, there is a Y/Bk that goes to pin 17 which is labeled 'self-test output'. I could not find any just tan wires but there is a listing for:
T-LG D - (Pin 22) - Fuel pump control
T-R D - (Pin 58) - Injector Bank 1
T-O D - (Pin 59) - Injector Bank 2.

The only way to really know is what the pin position at the connector is.

Regards
Harry

Re: ECU Harness

Reply #3 – January 04, 2026, 05:15:47 PM

I don't know if these were always loose? Car ran well and I had no problem with the ECU somewhat exposed. Wasn't until I recently tucked it up better that I noticed these two dangling connectors. Researching the numbers, I found the car came from the factory as a 3.8 v-6.
I'm after a diagram of the color code leads or pin configuration of that ECU connector. Attached are pictures. Both loose wire have been spliced ? to add more to the questions?

Re: ECU Harness

Reply #4 – January 04, 2026, 05:22:49 PM

Manuals

Third stuff is down towards the bottom.

Re: ECU Harness

Reply #5 – January 04, 2026, 05:48:25 PM

Got it. a lot to digest. Thanks Chuck

Re: ECU Harness

Reply #6 – January 04, 2026, 11:09:05 PM

Your pics don't tell a complete story to be able to help better.

Might be an issue with one of the injector circuits, but hard to say.

Re: ECU Harness

Reply #7 – January 06, 2026, 05:07:30 PM

Pics