Left blinker/brake light not working from my vehicle

[joetc]

After troubleshooting my trailer for an hour or more I've determined (100%) that the non working blinker/brake light on my trailer is actually a problem with the wiring on my vehicle and not my trailer. Everything at the plug and as far as I can follow the wire looks fine and in very good condition. Are there fuses connected to my trailer wiring in my vehicle that could cause this? Does my trailer wiring come all the way up front under the hood somewhere (chevy trailblazer)? Any ideas on where to look or start trouble shooting? I can only imagine how much a simple wire fix would cost if I brought it in.

Thanks,

Joe

[joetc]

And if it matters, my vehicle lights all work fine.

[perchjerker]

have you tried changing the bulb?

they can appear fine but cause strange problems from internal grounding or short issues

[joetc]

It's not the bulb. I have sealed led lights and I have put the light on the other side of the trailer and it works fine. It's definately my truck as I also hooked my truck up to another trailer and had the exact same issue.

Joe

[jfg]

Just had a similar problem with my Rangertrail attached to a GMC Yukon - no left trailer brake light but blinker worked. I checked the circuit on the vehicle wiring harness with a simple circuit tester I got at Napa. That showed the problem was in the truck. Dealer got a shot at fixing but said it was the trailer. It turns out that the hazard/flasher module needed replaced. Part was buried behind the interior fuse panel. About $35 at Napa for the part. Fixed it right away. Had to take off the cover panel on the dash below the steering wheel. The part is about 1x1x3-4 inches long.

[mudpuppy]

In my Dad's Trailblazer there's two fuse boxes. We had a similar problem and couldn't figure out why we couldn't find the blown fuse to the trailer lights. I asked him if there was any other fuses and he said no. So he finally dug out the owners manual and "surprise", I found the fuses to the rear of the vehicle are under the back seat on the drivers side. I'd look there.

[rebs]

I had the same problem with my 03 Yukon and it was a module. Does your have a red tail light and amber turn signal light ? The module was alittle expensive around 55.00 if I remember right. It was not a flasher module but a module that had to do with the red tail and brake light and amber turn signal light on the rear of the vehicle.
This could be your problem as well.

[we16]

You also have a set of fuses just for the trailer wiring.
In my Chev truck, they are in the side of the dash.
Open drivers to get to them

[joetc]

Thanks everyone. Found the fuse box and that was it, blown left trailer blinker fuse. Glad to find that as it's definately the cheapest fix.

Joe

[Borch]

Originally Posted by joetc

And if it matters, my vehicle lights all work fine.

Bad flasher module in your vehicle. Just had the same issue with my 2003 Silverado 1500HD. Replaced the module and all is good now. In my truck it's located behind the fuse box and I needed to pull my lower dash off to access it. Part cost was $85 at Napa.