2017 Silverado LT HELP with trailer lights

[Eyecon21]

Hi there,

 

So I'm having trouble with my trailer lights. Truck end has both a 7 and 4 pin connector. I have an adapter with test LEDs and everything seems fine (indicator shows when running lights on, left and right turn, etc). However I am not getting lights at the trailer. I've gotten the turn and brake lights to work at one point but no running lights. I've run all new wire with new fixtures, re drilled fresh holes for ground, etc... still fighting this thing. Trailer lights and I never seem to get along for something that should take no more than an hour and a few beers to do. Any help or suggestions would be appreciated, thanks

[XSKIER]

If you are drinking a few (4-5) beers in an hour, it doesn't leave much time for wiring.

[Eyecon21]

lol touché however I moreso meant it should be relatively simple process, especially with a new truck... and new holes drilled for ground wires (one off the adapter at tongue of trailer and one at each fixture)

[2017HD]

Wow, I have not heard of such a problem - esp when you have rewired the trailer. The fact that your tester shows the truck is putting out the correct voltages to the correct places - the problem must be in the trailer. But where? Back to basics - try to get the tail and marker lights working find that wire and trace it to each light. Then work on the brake and turns. I know some fixtures allow you to run both a hot and ground - try that.

[XSKIER]

I've only hauled one trailer with my 17, and it was no issue. However, on my 07 avy I hauled lots of different trailers, some in really poor electric state (customers boats for repair). About twice a month a shorted trailer wire would blow a trailer circuit fuse under the hood. Those little 4 way LED jobbies came on the scene back then, so I picked one up to leave in the truck, to quickly verify my equipment vs customer's. I found it takes about .001 amp to light the tester LED, and won't show if you have enough amperage available to light a trailer circuit. Maybe double check your trailer with the amperage setting on your multi meter. Then check for truck voltage drop at the trailer socket and fuse panel.

[Eyecon21]

I will have to do a test at the truck socket and see I suppose. I would have thought a brand new 2017 vehicle would be fine and no issues but apparently not. It's hard to imagine it being the trailer end especially with all that I have done. Unless there's something I'm missing here, truck or trailer end, I have to assume it's the truck and problem with wiring, etc, from the socket

[BigBadSierra]

Of of OEM wiring if all the pins test okay it's the trailer that has the issue.

 

I've found newer vehicles like good grounds in the trailer. I have had a utility trailer since 2005 never had to many issues with it.

 

But on the 2014 pickup the lights where dim or didn't work turned out I had to clean up and re ground the lights on the trailer.

 

I instead chose to upgrade the trailer to all LED lights now it's great.

 

In the process of doing the something to my Travel trailer now.

[PhilB]

I was checking the lights on my bass boat trailer that I hadn't used in 10 years. I was having troubles with the running lights also. Checked grounds and lights and looked for cuts in the wires. Found nothing. Went to move the trailer when it was dark and all of the lights worked. I figured out that my light sensor for the auto headlights was keeping the running lights from coming on even though I used the switch for all lights on. I put a towel over the sensor and the lights would come on. Maybe you have a similar issue? Just a thought.

[Eyecon21]

Ok so rebooked up the lights, all grounds to bare metal of trailer, everything wiring wise seems ok. With 2017 Silverado LT, it has automatic lights as the poster above described. So when the "running lights" are off, I have signals and brakes working. The second the "running lights" go on, they stop working. However, the side lamps of the back fixtures stay on? I honestly feel like I'm missing something here, possibly a relay fuse missing? I have no clue at this point.

[Eyecon21]

Could this possibly be an issue with a bad relay? I relooked over the fuse panel diagram, obviously have checked fuses and they are ok, but noticed a spot for a trailer park lamp relay... idk what my chances are that it is bad?

[crankman]

I would ditch the LED test light thing and get a 12v test light with the sharp prong on the end. Start at the beginning at your 7 way pug on your truck. Go thru all the functions one at a time verify there all providing a 12 volt at the 7 way. Then you know your good there, move to the trailer connector they can be problematic. Verify one at a time power is going thru trailer connector into the trailer wiring and just keep working back until its fixed.

[Eyecon21]

So I finally figured it out. Tested the truck with a multimeter and everything was ok there. So eventually just kind of took a step back and it finally clicked..... the fixtures as I had mentioned have their own individual ground. There's also a ground off the trailer adapter. After looking at how my trailer is designed, the tongue is slotted then bolted to the "fork/axel" area,.. thus creating a poor ground situation at the fixtures and not allowing a complete and clean circuit. Solution... spliced off the fixture grounds to run up to front of trailer where adapter ground is connected. Everything working as it now should.

[crankman]

Cool glad you got it squared away

[NEFisher11]

Nice to see you figured it out. I have been following your progress curious as to what the verdict would be