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2001 f350 diesel 4x Third owner.
Removing an old DrawTite brake controller that was attached with wire nuts. The 4 protruding wires are plugged in what appears to be the correct factory connector. Visually, it all looks good.
When I test the red wire that goes into the controller, it acts as a ground when the brake pedal isn’t depressed. Is this correct? From what I’m reading, if it goes to ground, it can kill the unit. Perhaps that’s why the DrawTite was bad. Brakes not depressed. Brakes depressed.
The black wire is not ground, the white wire is ground, black is B+.
white to black should read 12v
white to red should read 0v brakes NOT applied
white to red should read 12v brakes applied
white to blue should read 0v
Thank you.
I’m installing Prodigy P2 to replace the DrawTite.
That all checks out.
What concerns me is the red wire acts as a ground when the brakes are not applied. I understand that will short out the controller when using manual brakes. It makes me wonder if the factory connector is wired correctly or possibly I need a different adapter.
The brake light bulbs themselves are low resistance so it makes the red wire look like it’s a ground but your actually seeing the filament to ground. If the red wire was actually ground then the fuse for the brake lights would blow every time you pressed the brake pedal.
Edit:Another check you can do is look at the ford side of the trailer brake plug and it should have a green wire going to your red wire, if the wire is red with green stripe then there will be issues.
The brake light bulbs themselves are low resistance so it makes the red wire look like it’s a ground but your actually seeing the filament to ground. If the red wire was actually ground then the fuse for the brake lights would blow every time you pressed the brake pedal.
Edit:Another check you can do is look at the ford side of the trailer brake plug and it should have a green wire going to your red wire, if the wire is red with green stripe then there will be issues.
That makes good sense. I figured I was being over cautious. Over complicating an easy task. Now I know. Thank you.
