New trailer lights not working

Discussion in 'Boats and Motors' started by Spence88, Aug 4, 2008.

  1. OK, so I replaced the trailer lights because one was all cracked up. I figured I'd replace both so they match - and they are only 12 bucks apiece.

    So, snip the wires, remove old lights. Rewire and check - and no @#$%^ lights. They don't work and I can't figure out why? Gotta be something I'm just not thinking of right??

    I mean, the damn things worked right before I swapped for the new ones. Ground wire is grounded, wires are connected to where they are supposed to be...

    Any thoughts?
  2. Seems odd that neither would work. Check at the new lights with a voltmeter to make sure you still have power at the light. If not, check your way backward till you find the problem. Do the car/truck lights still work? Possibly a fuse? Did you make sure the old wires were clean where you connected the new lights? If have power at the light, pull and reinsert the bulbs. If still don't work, try a bulb from the old light.

  3. did you look to see if theres blubs in the new lights?? if so , 99.9% of the time lights don;t work its the ground , go have three more beers and relook the work you;ve done , p/s two beers won;t do it , its gotta be three. lol
  4. ezbite

    ezbite the Susan Lucci of OGF

    when you stripped off the insulation from the old wire what color was the wire? bright copper or a black kind of color? if the wire is tinned, it will be silver, if its just vinyl coated wire you have on the trailer, check your connection again. if the wires black after you strip the insulation, scrape it with a sharp edge until the corrosion is gone and its bright copper.
  5. I had a issue just like yours and I did have the ground wire tight on a screw but it still wasnt grounded right because the paint or something on the trailer. Maybe you got a issue like that.
  6. not to hyjack the thread but I've got a problem with new trailer lights also. Hooked everything up and running lights and turn signals work good but only one break light works. The other instead of getting brighter turns off:confused: any suggestions???
  7. Junkyard, Its your ground. Mine does the same thing. After a few mins.
    down the road everything starts working again. Its probably grounded
    thru the hitch. Take a little sand paper and clean the rust out of your
  8. Hook N Book

    Hook N Book The Original Hot Rod Staff Member


  9. Ground!! Check the wire that should be connected to trailer frame near reciever, take it off and clean it. If symptoms persist do the same at each tail light.
  10. Ditto on below post, I had a lot of trouble with my lights and started to trace them back to truck and found 3 spots where the insulation had rubbed off the wire because it was contacting the trailer. Rather than patch it I rewired the trailer, it was easy and I have solved all problems.

    one week later my uncle had lights that would work intermittently, we rewired his trailer in about 1 hour very easy, especially when you take boat to the lake and put it in the water and work on the trailer without the boat on it

    good luck
  11. UFM82

    UFM82 The one others want to be

    The proper way to ground your trailer is as follows:

    1) Truck- drill a 3/16" hole somewhere in the frame near the location that the plug is going to be. Crimp, solder and then shrink-wrap a YELLOW 1/4" eye connector onto a length of 10 gauge tinned wire of the proper length to reach from the frame to the plug. Screw that to the frame with a galvanized screw that will screw into the frame. I prefer a 1/4" self-tapping screw as it will cut threads into the frame in the pilot hole and provide a good ground. ( I use the hex-head type so I can use a ratchet.) On the other end, crimp, solder and shrink-wrap whatever connector is needed for the plug.

    2) Trailer- Crimp, solder and shrink-wrap whatever connector you need for the trailer end of the harness. Run a length of 10 gauge tinned wire back from the trailer plug to the front of the trailer tube where the hitch bolts on. Again, drill a 3/16" hole in the trailer tube. Crimp, solder and shrink-wrap a YELLOW 1/4" eye connector to the wire and attach it to the trailer tube with a 1/4" self-tapping screw.

    This will properly ground your trailer to your truck EVERY time. relying on your hitch to ground properly is a major cause of lighting issues and grounds are 99.9% of the time the culprit got lights not working.

  12. I had the same problem saturday only one side lit. I sprayed ALL connections with electric contact cleaner. After about ten minutes everything worked fine.
    Try it.
  13. Dont forget to check you fuses on your fuse block in truck.... this has happen to use as well on our older boats...

  14. freyedknot

    freyedknot useless poster

    mine wee not working so i reworked them from front to back. threaded new 4 flat thru the trailer and reworked all ground wire connection ,but still had no ligts in back? i ended up running a ground wire from front to back and got them working. my side markeres worked but not the tailights untill i ran the ground wire back to them?