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Thread: No brake lights on trailer

  1. #1
    Colonel CHIEFSONN's Avatar
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    Default No brake lights on truck & trailer

    Last night after hooking up my trailer m105 to my m932a2 I have no brake lights, the rest of the lights work,rt turn left turn & running light. how do I test the plug or truck s for the problem so come Thursday i will have brake light . thanks
    Last edited by CHIEFSONN; 10-15-2019 at 13:12.
    1953 REO M35a2 Multi fuel Deuce /NJ National Guard
    1954 Checker Cab M105a2 also from NJ National Guard
    1989 M932a2 tractor w/w converted to a M932a2 troop transport, with 3' removed from a 14' drop down side bed. MB AFB
    1967 M105a2 ?
    1970 Kaiser M816 Wrecker Cummins
    1973 AMG M35a2c w/w Multi fuel Deuce

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    4 Star General jasonjc's Avatar
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    Check the ground on the trailer. If you have right and left turns you should have brake lights. Same wires and bulbs.
    "It is a proven fact that you cannot idiot proof anything due to Mother Nature's ability to constantly upgrade the common idiot." WM

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    4 Star General Trailboss's Avatar
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    If the turn signals and hazard lights are working, I'm thinking probably the switch at the brake pedal.
    Hoarder of M1 Garands and Military Vehicles.

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    General Ajax MD's Avatar
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    The initial post is a bit ambiguous.

    WHERE have you lost brake lights- The trailer? The truck? Both?
    IF brake lights are lost on both, What happens when you unplug the trailer? Do the truck brake lights function again? Are they still out?
    Motorpool:

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    dumpsterlandingfromorbit! gimpyrobb's Avatar
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    In the past, I've had issues with the ground on the truck side.

    A dvm hooked to ground on the vehicle then plugged into each pin should tell you which wire on the truck is or isn't working. Gimme some time and I will find the pins you need to test.
    Don't worry about the size difference

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    dumpsterlandingfromorbit! gimpyrobb's Avatar
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    Don't worry about the size difference

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    clinto (10-15-2019)

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    Colonel CHIEFSONN's Avatar
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    Ajax MD with the trailer unplugged the truck still has no brake lights
    Last edited by CHIEFSONN; 10-15-2019 at 18:21.
    1953 REO M35a2 Multi fuel Deuce /NJ National Guard
    1954 Checker Cab M105a2 also from NJ National Guard
    1989 M932a2 tractor w/w converted to a M932a2 troop transport, with 3' removed from a 14' drop down side bed. MB AFB
    1967 M105a2 ?
    1970 Kaiser M816 Wrecker Cummins
    1973 AMG M35a2c w/w Multi fuel Deuce

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    4 Star General juanprado's Avatar
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    If this is for the m939 series, I suspect the stoplight switch is bad. It is on the metal airline hugging the frame down from the cab. The oe has military packard connections. Easiest fix is haldex universal civy 2 terminal air brake switch and just make an adapter to your military wiring if you do not want to cut oe wiring. Napa or any hd store

    https://www.haldex.com/en/na/electri...tches/be13250/
    1984 M923 "Maj. Zippidy" who now is equipped like a M925A1
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    1990 Kasel M101A2
    1968 Case Master M101A1 with fuel tank and gen set up
    1991 Eastern Technologies M105A2
    60's ? m116a1? radar trailer flatbed
    xm1073 flat bed 7 1/2 ton


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