Forum Discussion

ccjmt4's avatar
ccjmt4
Explorer
Apr 30, 2014

Stop and turn signal issue

I tested my trailer lights and have found an issue. The tail light(head light) works on the left and right side of the trailer. However, the stop and turn signal does not work on the left, but will on the right. Both the stop and turn signal works on the TV just fine. I have tested the plug and find no juice is coming from the TV plug on the stop/signal prong. I have checked the fuses and all appear fine. Any suggestions on what the issue might be? TV is a 2002 Chevy 2500HD Crew Cab with factory standard wiring harness.
Tow Vehicles

8 Replies

  • ccjmt4's avatar
    ccjmt4
    Explorer
    May 02, 2014
    Thanks for the help. I didn't know there was a separate fuse for the trailer lights. I found the 10 amp fuse was blown. Replaced it and everything works great
  • vortec22's avatar
    vortec22
    Explorer
    May 01, 2014
    I would second the fuses. I didn't realize my '03 had separate fuses for truck and trailer till I ran into this same issue.
  • Campfire_Time's avatar
    Campfire_Time
    Explorer
    May 01, 2014
    I'd be willing to bet that its your turn signal/hazard flasher unit. My '03 Trailblazer had exactly the same behavior about 2 years ago, right down the pattern of what works and what doesn't. I spent 2 hours the morning of a trip and even replaced the receptacle. No dice. I went anyway and did more research when I returned. I found a thread somewhere where someone had the same issue. I was skeptical but out of options. The new flasher unit fixed the problem.
  • msjdbman's avatar
    msjdbman
    Explorer
    Apr 30, 2014
    Just a reminder in case you didn't remember, but the trailer feed has separate fuses from the truck. They are in the "under hood panel" if I remember correctly.
  • Campfire_Time's avatar
    Campfire_Time
    Explorer
    Apr 30, 2014
    I had this happen on my old 2003 Trailblazer. Exactly the same pattern. I spent two hours fooling with it on the morning of a trip, replaced the factory plug, etc. That still didn't fix it.

    The issue was a bad turn signal/hazard flasher unit. On GMs, at least in that era, the flasher is directly tied in to the trailer lighting system. They are not cheap, $40-$60.
  • JN_B's avatar
    JN_B
    Explorer
    Apr 30, 2014
    First thing I would do, plug it into another truck and see if the problem repeats. That will narrow it down right away.

    Then,

    Check all fuses and plugs. I just replaced my 2YO female 7pin on the truck, completely corroded. My new one, I covered all connections in dielectric grease, then completely wrapped it in electrical tape, followed up with gorilla tape. Yes, that is over top of standard plastic cover supplied with the 7 pin plug.
  • rhochnadel's avatar
    rhochnadel
    Explorer
    Apr 30, 2014
    Had that happen to me, checked plug, wiring, and finally found the Chevrolet had a separate fuse for the trailer lights. Check your fuses again.

About Travel Trailer Group

44,043 PostsLatest Activity: Jul 20, 2025