Check Left Trailer Turn Signal Lamp - Momentum 395M 2020

[Jimbo58]

First post in a while. Any issues I had in the past, I looked to see of anyone else had a solution and pretty much did so I didn't post.

At any rate, this isn't a critical issue, mote of a minor annoyance.

Hooked up our 2020 Momentum to our 2020 GMC Sierra Denali to the plug in the bed. Got the message that trailer was detected and connections were good. We do a physical brake and light check before we take off. Just did a check prior to posting this and here is the issue.

When I turn on the fog lights (which turns on the side slights on the trailer), I get a message on the dash "Check Left Trailer Turn Signal Lamp" and I get a fast turn signal which indicates a turn signal lamp is out. Before I turned on the fog lights, I did a check first and everything is working correctly.

I turn off the fog lights, wait about 30 seconds and try the turn signal again, all good.

Just for grins, I checked with the connections with my plug in the bumper, same issue.

My guess was an issue with the plug in the truck bed but since I got the same message with the bumper plug, not sure what it is.

Any ideas?

Thanks in advance!

[jkwilson]

My engineering instinct, combined with hauling farm, boat and camping trailers says to check the main ground and the ground at the suspect light.

[Jimbo58]

Should be fairly simple to check...thanks!

[Second Chance]

Another place to check connections is the junction box up inside the pin box. It's a rat's nest in there with lots of wire nuts. It's not uncommon for things to jiggle loose up in there.

Rob

[geotex1]

Another place to check connections is the junction box up inside the pin box. It's a rat's nest in there with lots of wire nuts. It's not uncommon for things to jiggle loose up in there.

Rob

Sure is, and GD combines way too many grounds with a single wire nut here!!! I discovered this when I wired in my TST repeater here, and corrected the situation by putting a stud post in the box and crimping on a lot of ring terminals.