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mcewena's avatar
mcewena
Explorer
May 02, 2013

Odd 7 to 4 wiring problem

I've recently installed a brake controller on my RV as I'd planned to tow a trailer. I have confirmed it's working with a 7 pin LED tester.

Now I'm flat towing a car and I just want marker/brake lights, when I put in a 7 to 4 adapter and use a 4 pin LED tester I get left and right signals, tail lights but no brake lights even though the 7 pin tester showed the brake light working. I've tried 2 different 7 to 4 adapters.

Any ideas?

Thanks,

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