Forum Discussion

cbwallace's avatar
cbwallace
Explorer
Aug 18, 2019

Trailer brakes stop working when headlights are on

My Reflection has developed an issue where the trailer brakes stop working when my headlights are on. In the truck I get a Check Trailer Wiring message. When this occurs the trailer brakes don't work. When I turn the headlights off trailer brakes work again. On may last trip this also happened about 50% of the time I used a turn signal. I have checked 7-pin connector and find no corrosion. I am thinking it is a grounding issue but not sure what to check in the 5th wheel, any suggestions?

Chris
  • beemerphile1's avatar
    beemerphile1
    Explorer
    Aug 18, 2019
    I agree about it probably being a ground issue. Did you test the resistance from the ground wire in the umbilical and the frame?

    Look underneath and check/clean/reattach all the ground connections on the frame.

    How about the truck side? Is it grounded to the frame somewhere in the rear?
  • agesilaus's avatar
    agesilaus
    Explorer III
    Aug 18, 2019
    A short somewhere in the wiring? I just spent an afternoon patching my cable after it got some road rash

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