Hey Obie66, welcome to the forum.
Could be a short between the brake lights and the brake wire for the trailer. Do you have a multimeter or a 12V test light that you can use to do some tests?
Do you have a friend or relative that tows with a 7 pin that you could see if the problem occurs with their vehicle? That would at least allow you to focus on the tow vehicle or the trailer.
You stated
obie66 wrote:
I pulled over, unplugged my trailer plug (round 7 way), disconnected the emergency plug and re-inserted. The problem was gone.
Jeff
How did you disconnect the emergency plug( breakaway switch)? As far as I know the only two parts to the emergency plug are the cable/pin, and a positive wire to the battery. Are you saying you pulled and reinserted the pin?
Or did you disconnect the positive wire to the breakaway switch?
If you pull the power wire for the breakaway switch does the problem go away?
