1988-1990 Wiring Help - Ford Mustang Forums : Corral.net Mustang Forum
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post #1 of 1 Old 02-12-2017, 08:20 PM Thread Starter
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1988-1990 Wiring Help

Hello everyone, Ive been following a few of the diagrams on very useful.com to help identify all of the plugs on my wiring harness but I'm still not sure about a couple and if they are needed and where they would go or plug into. Any help would be greatly appreciated.

A little background before I get to the photos, I'm building a 5.0 swapped 1989 Mazda RX-7. Everything on the car will be ran off of a speedway harness as of now. Currently I've gone through each wire on the plugs that I'm not sure of and tried to trace them back to the ECU plug with a ohms meter to help identify what they might be. These last few I have had no luck and I can't seem to determine if they are needed at all. So again any help would be greatly appreciated.

All of these are at the very end of the harness which I would assume would be somewhere near the drivers front?

These next two are right near the ECU plug. I assume the green plug is what connects to things behind the dash on a fox body and the other one I believe to be the EEC relay?

I apologize for this photo, its hard to see exactly what the plug looks like but I can try to grab more if it would help. There are four plugs in this location. EGR, and 2 Air Management solenoid plugs. Depending on what picture you look at though these two seem to be labeled as Thermactor Air Bypass/diverter solenoids. If thats the case it leads me to believe that the last one is an A/C pressure switch?

These next two are right near the self test ports in the harness. Every diagram I see says that there should be a single brown eight pin connector here. I can't seem to find any info about what these are and if they are needed in order for the car to run smoothly.

Last but not least we have this one that is right near the HEGO connector. Im thinking that this may be the connection for the fuel pump relay possibly or the wide open throttle A/C cut off relay.

I figured I should show you guys what I'm working on as well. Ive done everything on the car myself up until this point and want to know what everything does so that I can diagnose any issues in the future.

Thank you again for any help

Attached Images
File Type: jpg wiring1.jpg (53.7 KB, 6 views)
File Type: jpg wiring2.jpg (66.1 KB, 6 views)
File Type: jpg wiring3.jpg (80.7 KB, 6 views)
File Type: jpg wiring4.jpg (87.9 KB, 6 views)
File Type: jpg wiring5.jpg (61.0 KB, 5 views)
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