Trailer Lights

Discussion in 'Trucks and Trailers' started by bp418, Aug 13, 2005.

  1. bp418

    bp418 LawnSite Member
    Messages: 33

    I have a 5x10 trailer, it's 1 year old, bought new. The driver's side trailer light stopped working. I replaced the bulb, yet still no go. I went to Northern Tool and purchased a new entire light and installed it. It still will not work. I checked the ground and wires, none appear broken. Passenger side trailer light works great. I have a 2004 Ford F150 4x4 with the round and straight plug, currently using the straight plug, which according to my volt meter is getting power. Should I buy an adapter for the round plug and give that a try or replace on the hitch wiring in the truck???
  2. Roger

    Roger LawnSite Fanatic
    Messages: 5,943

    I presume your mention of "straight plug" means a standard 4-wire connector. Do we understand to to mean you have power on three of the connectors at the truck? Three connectors: tail, right turn/stop, left turn/stop -- the fourth connector being ground. Using your multi-tester, are you able to put the ground prong of the tester into the ground of the connector, then show power on your tester of 12 vdc for each of the other three connectors?

    If that is the case, then an adapter to a round plug, or replacing wiring in the truck is not useful.

    When you got your new light set from Northern Tool, did you lay it beside the trailer and show that all lights were working properly BEFORE making the install? This would have been the logical thing to do. If so, then something has been destroyed on the install, making the attachments to the trailer frame, etc. And, you should be able to trace all your install work to determine where you may have destroyed a wire.

    Also, you may have not made the ground connection (white wire) properly to the trailer frame. The metal needs to be bare and clean so that a good ground from the wire to the frame is established.

    ... just my observations -- may or may not apply to your situation.

    SHOWCASE LAWNS LLC LawnSite Member
    Messages: 238

    do you have a friend that is an electrician ? i bet he can find the problem in 10 minutes......tell him you will treat for a trip to HOOTERS OR TGIFS IF HE FIXES IT. ITS A EITHER A BAD CONNECTION,BROKEN WIRE OR SOMETHING OF THAT NATURE.......AN EXPERIENCED ELECTRICIAN WILL FIND IT IN A HEARTBEAT.
  4. bp418

    bp418 LawnSite Member
    Messages: 33

    I tested the light I bought and it works, also found both trailer lights work with the headlights on. I hooked a battery charger up to the four pin connector on the trailer side and both trailer lights worked, however as soon as I plugged it in to the truck, only one side without headlights on works. I'm headed to the Ford dealer on Monday to have them look at the trailer wiring up under the truck. thanks for the help.
  5. RonB

    RonB LawnSite Senior Member
    Messages: 427

    does the taillight on the TRUCK work?
  6. bp418

    bp418 LawnSite Member
    Messages: 33

    Yes, all lights on the truck work, it was bought new and has been garage kept.
  7. bobcatnj

    bobcatnj LawnSite Senior Member
    Messages: 687

    let me know what happens because i have the same problem with my 04 f250. the trailer lights only work when the headlights are on. i aslo keep blowing the trailer turn signal fuse in the trucks fuse box.
  8. bp418

    bp418 LawnSite Member
    Messages: 33

    PROBLEM SOLVED!! Fuse under the hood, left side/camper/trailer 10amp slot was blown. New fuse and all's good. Thanks for the help!!

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