Boat Trailer Tail Lights

[Rivergator]

I installed new LED tail lights on my trailer and I am pretty sure that the wiring was done right and I am also pretty sure that the problem is with the source, a 2004 Chevy Tahoe with factory towing package. Here is what happens: It does not matter whether the trailer is hooked up to the tow ball on the Tahoe or not. When I turn on the head lights, everything works fine on the Tahoe, but I have no tail lights on the trailer. Now I add to it the blinkers, they work just fine. Now I add to it the brakes. Now the tail lights on the trailer are both on if no blinker and if I add the blinkers to it, one tail light is on steady and the blinker side blinks just fine on either side. The same happens if I turn off the headlights on the tahoe. Everything works like it should, except that I have no running tail lights on the trailer. I know my grounds are good, otherwise nothing would work when disconnected from the tow ball. Any suggestions what I should look for?

 

[JimS123]

A similar thing happened to me once. You either have a short somewhere, a blown fuse in the Tahoe, or the Tahoe's wiring is compromised or shorted.

Check every single wire for a short to the trailer's frame. Check all the fuses in the Tahoe. Use a trouble light and check the Tahoe's trailer plug to verify that each leg is providing the power as expected. Finally, check the ground at the lights themselves to be sure each one is grounded to the frame. As a last resort, run a separate ground wire from each light to the frame.

 

[Rivergator]

I made it easy on myself and I had my brother come over with his Chevy truck and we tested the trailer on his truck and everything works like it is supposed to, which eliminates any problems with the wiring on my trailer. Then I did some more testing and sure enough I have no voltage on the brown wire coming out of the connector on my Tahoe. Now my question is, is the trailer wiring on a factory installed tow package on its own circuit with fuses or is it half ass spliced into the tail light wiring of the Tahoe by the factory? Does anyone happen to know?

 

[dingbat]

Now my question is, is the trailer wiring on a factory installed tow package on its own circuit with fuses or is it half ass spliced into the tail light wiring of the Tahoe by the factory? Does anyone happen to know?

Dedicated tow circuit on my 2001 Tahoe

 

[JimS123]

As I said before, BTDT. In my case the fuse in the towcar was burnt. Easy peasy fix - the fuses are easy to look at and a burnt one easy to spot.

Now, if you replace the fuse and it blows again, NOW you got a short in the car.

 

[airshot]

Never use your tow ball as a ground or you will have issues. Dedicated ground wire to trailer frame on mine with a jumper ground wire where frame sections have a joint and each light on the trailer has a ground to the frame. Each connection is sealed so no water touches any connection. Never had a problem in the 15 yrs I have been doing it this way !!

 

[JKLknik]

Ive switched to LED on three of my trailers and I bought everything through etrailer.com. The Optronics brand submersible trailer lights work very well and are well made. I haven’t had any issues with Optronics LEDs in the 10 years that they have been on my driftboat trailer. They also make several styles of trailer lights so they most likely have a model would be a direct swap with your current lights.

 

[Scott Danforth]

for what its worth, GM has separated all the trailer circuits onto their own fuses years ago starting in the 90's. so keep spares in the glove box.