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joshenj's avatar
joshenj
Explorer
Feb 25, 2019

Trouble with Left blinker light on travel trailer.

So when I hook my truck up to my travel trailer I can't get the left blinker to work on it. We took my buddy's truck who knew he was wired good and the blinker worked. So bulb is good and wiring on trailer seems like it should be good. Tested my truck side 7 pin connector with ohm meter and left blinker was registering and blinker on my truck works fine. Replaced entire 7 pin connector on my truck as well with no success. Still registering power to the connector but as soon as I hook it up to the trailer doesn't work on the trailer. Back my buddy's truck up again. Works just fine. Any ideas?
  • joshenj's avatar
    joshenj
    Explorer
    Feb 26, 2019
    Hey all, thanks for all the help. I had just gotten this truck and didn't even realize it had so many fuses! That's all it was. Thanks again.
  • Charlie_D_'s avatar
    Charlie_D_
    Explorer
    Feb 26, 2019
    Brake/tail light has 2 filaments. OP-thought I had the answer until you said it works when plugged to another truck.
  • Campfire_Time's avatar
    Campfire_Time
    Explorer
    Feb 25, 2019
    Very possible you have a bad flasher unit. I had something very similar happen on my old 2003 Trailblazer. I delayed going on a trip because of it, replacing the factory 7 pin connector as you did. Came back form the trip and learned about the flasher. Replaced it and problem solved.
  • enblethen's avatar
    enblethen
    Nomad
    Feb 25, 2019
    Have someone apply the service breaker to see if brake light comes on. The turn signal and brakes lights use the same filament on combined lights. That is if turn signals are red.
  • joshenj's avatar
    joshenj
    Explorer
    Feb 25, 2019
    I have a 2007 Chevy Diesel LBZ. Thanks for the fuse idea, I'll try that first.
  • enblethen's avatar
    enblethen
    Nomad
    Feb 25, 2019
    Blown fuse in truck! Some newer trucks have separate fuses for trailer connector. Check owner's manual.
  • RoyB's avatar
    RoyB
    Explorer II
    Feb 25, 2019
    I always use WD40 to spray into the 7-pin socket and move it all around to clean the contacts... I think we all have a can of WD40 and some DUCT TAPE on board... Even some bailing wire haha...

    Never leave home without them haha...

    Since you have replaced the 7-way connector it must be a ground or something not right with the leads feeding the rear hookup.

    My truck has the DUAL 7-way and four way trailer connector as a unit with spring door that is used for locking into the trailer plug...


    Google search

    Roy Ken
  • 1995brave's avatar
    1995brave
    Nomad
    Feb 25, 2019
    What kind of truck do you have? If it is a newer truck some of them come with fuses for the trailer hitch. It could be one of those fuses blown or corroded connection. Just putting a meter on the pin does not give it enough load to correctly check the current to the light. Even the LED testers do not put enough load to properly check for loose or corroded connections.

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