Running Light Circuit on TowReady T-One Vehicle Wiring Harness # 118521 Shuts Down

Question:

Some 17 months ago I purchased a Curt Hitch and wiring harness from you for my 2012 Honda Odyssey. I used it to haul my hardtop tent trailer last week and was driving at night, so I put on the head lights of the car and thus the running lights on the trailer. They stayed on for about three minutes and then went out. When I stopped to inspect them, all other lights were working on the car and trailer, i.e. brake lights, signal lights, head lights. When I turned the car off and then back on, the running lights would come on but then shut down in a few seconds. My son in law who is an electrician, checked the car with a meter and power is running from the fuse box and to the trailer re his tester even when the running lights go off. So he says there must be a thermal shut off in the wiring harness somewhere. Is that the case and if so how do I correct the problem? We tried this on a second trailer and the same thing happened. So in summary, all lights function when the running lights are turned on. The running lights will shut off shortly after but all other light functions continue to operate. HELP. John P.S. This was the first time I had hauled the trailer at night. I had passed safety inspections and my checking each time I hooked up because the running lights come on O.K. but unknown to me or inspectors they dont remain on very long initially, maybe a few minutes, and even shorter on subsequent tries.

asked by: John M

Expert Reply:

Thank you for your purchase from etrailer.

The problem you describe of just the running light circuit on your T-One Wiring Harness # 118521 going dead after a short period of use could have two causes. Either the harness is damaged internally or your trailer's running lights are drawing too much current (in excess of the unit's 7.5-amp capacity for this circuit). This 7.5-amp rating is fairly high, but still it could be the reason.

Since the unit appears to reset itself once you turn the lights off, this suggests the latter cause since the module will cool down once the load is removed.

If you have added new/additional running lights to your trailer, and particularly if these use standard incandescent type bulbs, the increased load may simply be overloading the harness. If this is not the case, and/or if you know the actual current demand from the trailer's running lights based on its manufacturer's specifications is within the harness' rating, then the unit may have suffered damage and requires replacement.

expert reply by: Adam R