LR4 problem with trailer brake/turn light

Discussion in 'LR4' started by jackkyxu, Jul 1, 2018.

  1. jackkyxu

    jackkyxu Full Access Member

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    I installed the OEM trailer harness myself on my LR4

    I am planning to move with a trailer in 2 weeks.


    Today I went to Uhaul to test the trailer, but there is no brake/turn light on the trailer


    any suggestion?

    PS: if a trailer is connected, is there anything I need to do on the console screen?

    thanks
     
    Last edited: Jul 1, 2018
  2. Lgibson

    Lgibson Full Access Member

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    I know that the trailer module needs more resistance than an LED trailer has in order to trigger the icon in the instrument panel. I do not remember if there is any functionality without resistor. Perhaps you should try one of the many adapters for incandescent to LED.
     
  3. Waterndirt

    Waterndirt Full Access Member

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    Ive heard if you swap one of the LED trailer lamps out for an incandescent, maybe a running light would be best?
     
  4. Travis

    Travis Member

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    I had the same issue on my 2011 LR4 when I hooked up my boat trailer which had LED turn signals. I had to buy a resistor (fairly large) from Radio Shack and splice it into my trailer wiring. After I did that, the LR4 recognized the trailer was connected. When the turn signals are on, a little icon of a trailer flashes in the instrument cluster also.
     
  5. Lgibson

    Lgibson Full Access Member

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    So here is a copy from my July ‘16 post detailing the resisitors it took to loght the trailer icon:
    Not having a variable resistor for testing I purchased a complete selection of mini-bulbs and proceded to test them in order of draw at the LR4's trailer connector. Not until I reached the one drawing 14.4 watts did the trailer icon in the cluster light up. The charts show 12 volts at 10 ohms will use 14.4 watts. I bought three 10 ohm 20 watt resistors off Amazon or Ebay and inserted them in the LED leads under the trailer bumper, one for running lights and one for each side. For me with only one trailer this was a good solution.
     
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  6. jackkyxu

    jackkyxu Full Access Member

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    how large is your resistor? 100 ohm or 10 ohm?

    thanks
     
  7. Lgibson

    Lgibson Full Access Member

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    10 ohm, 20 watt
     
  8. jackkyxu

    jackkyxu Full Access Member

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    I can not do anything on the Uhual trailer

    what about those etrailer adapter with resistor?

    the specialist shop told me yesterday that I installed an LR3 harness, which was a joke

    they tried to sell me another one from Atlanta British, claiming it is LR4, and the model is exactly same as what I got
     
  9. Lgibson

    Lgibson Full Access Member

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    I took one of those adapters apart once and it contained 3 100 ohm resistors, one for each circuit, maybe enough to talk to the trailer but not nearly enough to activate your trailer module/icon.
     
  10. jackkyxu

    jackkyxu Full Access Member

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    how sure are you about those adapter with resistor built-in? if it can just make the trailer lights working I am good

    I can deal with the 10 ohm issue later of triggering the trailer module

    bow and thanks
     

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