Engine overheat help

You could try to follow the black with wight wire at the plate lamp to where it terminates to ground. Might have to peel the conduit back be careful cutting it you don’t Nick the wires.

 

Keep following where they go.

 

Or use your test light connected to the positive battery terminal to confirm the ground is good. Red jumper cable connected to pos be careful with the other end it can not touch metal on the vehicle. Connect test light to that end gently poke the metal in the socket that is attached to the black with wight wire. It should light up bright.

 

One of those is black with wight the other is violet with wight make sure you get the right one.

 

Jumper cable to neg terminal other end to meter lead in in ohm mode seccond lead from meter to black with wight wire. Less than 5 ohm is spec but lower number the better.

 

Do a voltage drop test as well if possible. Many times a wire will test fine with no load. I know zero about fords nor will I ever but sounds a lot like a corrosion issue somewhere to me causing the BCM to not know what’s going on. Again multiplex electrical is just awesome when a problem arises.

 

Well Seasoned did you find next problem yet..
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Yep there a better tools and testing procedures but I was trying to explain how to do the test with what he had on hand. Loaded voltage drop is the best test. In this situation. Can be very confusing without some electrical experience.