lights on trailer on when driving

[Chad_Jen]

When bringing my trailer home over the weekend I noticed that the lights to my truck ('14 Chevy Silverado) were on (not just the DRLs but the actual headlights and taillights). I have the light switch set to "Auto" so I don't have to worry about them. I noticed when I looked in the mirror that the marker lights for the trailer weren't on. I think (but don't remember for sure) that in the past the lights for the trailer have come on when the ones for the truck did, even with the "Auto" setting on. I turned the knob to turn the lights on the old fashioned way and the ones for the trailer came on. Shouldn't the lights for the trailer be when the truck's are, even if the truck's selector is on Auto, or am I missing something?

[Chad_Jen]

Bobbo wrote:

Chad/Jen wrote:

Bobbo wrote:

Chad/Jen wrote:
When bringing my trailer home over the weekend I noticed that the lights to my truck ('14 Chevy Silverado) were on (not just the DRLs but the actual headlights and taillights).

Since you can't see either the headlights or the tail lights from the driver's seat, how do you know they were on?

The lights on the dash and control panel came on. Those aren't on with just the DRLs.

I have a 2017 F-150 XLT and the dash and control panel lights don't come on with the headlights. They have their own light sensor. In modern vehicles, they may not be a good indicator that the headlights are on. Test that the next time. When that happens again, stop and get out of your vehicle and look at the vehicle tail lights to see if they are on.

Ah...I didn't realize that. Thanks...I'll have to check it out.

[Chad_Jen]

All I could afford wrote:
I work with a guy that has a 2015 Silverado 1500. I believe that would be the same design as yours. We work different shifts, but if I run into him in the next few days I will try to check his seven pin connector to see if the marker light pin gets energized when auto lamps come on, and report back to you.

I believe you're right. Thanks.

[Bobbo]

Chad/Jen wrote:

Bobbo wrote:

Chad/Jen wrote:
When bringing my trailer home over the weekend I noticed that the lights to my truck ('14 Chevy Silverado) were on (not just the DRLs but the actual headlights and taillights).

Since you can't see either the headlights or the tail lights from the driver's seat, how do you know they were on?

The lights on the dash and control panel came on. Those aren't on with just the DRLs.

I have a 2017 F-150 XLT and the dash and control panel lights don't come on with the headlights. They have their own light sensor. In modern vehicles, they may not be a good indicator that the headlights are on. Test that the next time. When that happens again, stop and get out of your vehicle and look at the vehicle tail lights to see if they are on.

[All_I_could_aff]

I work with a guy that has a 2015 Silverado 1500. I believe that would be the same design as yours. We work different shifts, but if I run into him in the next few days I will try to check his seven pin connector to see if the marker light pin gets energized when auto lamps come on, and report back to you.

[Chad_Jen]

bobndot wrote:

Chad/Jen wrote:

bobndot wrote:
Might be a ground issue on the trailer. Unplug the trailer and put a tester on the 7 way plug on the truck to see if you have power at those pins. If so, its the TT and probably a ground.

If it's a ground problem (with either the truck to TT) why would they work if I turned the knob to on but didn't if I left it in Auto? I'd think they'd either work all the time or none of it.

Sorry I missed that part of your post. I would test the plug to see what's coming thru the plug in both situations anyway.

Did you look at the Silverado forums ? one of the links show where to supply your vin# to GM customer care posted by Jennifer T .
There might be that one piece of info on the chev forum to provide you an answer.

http://www.silveradosierra.com/towing-trailers/no-trailer-running-lights-t629698.html

http://www.silveradosierra.com/electrical/trailer-running-lights-are-not-working-t134298.html

Thanks, I'll look at those too.

[Chad_Jen]

owenssailor wrote:
When the switch was on auto in daylight are you positive that the headlights were on and not just the DRL's. It is unlikely that the headlights would be on in daylight when on the auto setting.

When just the DRL's are on the TV tailights are not on and there are no trailer running or tailights on either.

When I check lights each time to tow I turn the headlight switch to parking GM auto system here in Canada for 20 years.

Yeah, they were on. It was dark and rainy out.

[Chad_Jen]

Bobbo wrote:

Chad/Jen wrote:
When bringing my trailer home over the weekend I noticed that the lights to my truck ('14 Chevy Silverado) were on (not just the DRLs but the actual headlights and taillights).

Since you can't see either the headlights or the tail lights from the driver's seat, how do you know they were on?

The lights on the dash and control panel came on. Those aren't on with just the DRLs.

[owenssailor]

When the switch was on auto in daylight are you positive that the headlights were on and not just the DRL's. It is unlikely that the headlights would be on in daylight when on the auto setting.

When just the DRL's are on the TV tailights are not on and there are no trailer running or tailights on either.

When I check lights each time to tow I turn the headlight switch to parking GM auto system here in Canada for 20 years.

[bobndot]

Chad/Jen wrote:

bobndot wrote:
Might be a ground issue on the trailer. Unplug the trailer and put a tester on the 7 way plug on the truck to see if you have power at those pins. If so, its the TT and probably a ground.

If it's a ground problem (with either the truck to TT) why would they work if I turned the knob to on but didn't if I left it in Auto? I'd think they'd either work all the time or none of it.

Sorry I missed that part of your post. I would test the plug to see what's coming thru the plug in both situations anyway.

Did you look at the Silverado forums ? one of the links show where to supply your vin# to GM customer care posted by Jennifer T .
There might be that one piece of info on the chev forum to provide you an answer.

http://www.silveradosierra.com/towing-trailers/no-trailer-running-lights-t629698.html

http://www.silveradosierra.com/electrical/trailer-running-lights-are-not-working-t134298.html

[rbpru]

Some folks like their lights on while traveling, that is nothing new, I have friends who have done this for years.

I like the "auto" feature but the tape on the sensor would work except the dash lights would dim.

Mostly a matter of what you prefer.

Be safe

[dodge_guy]

The trailer lights should mimic the truck lights. If they aren’t there is an issue somewhere!

[Lwiddis]

"I always leave my 2012 Silverado's light switch in the AUTO mode and let it determine when full lighting should be on..."

While they are better now, I don't always let my Tahoe determine that decision. I turn them on sometimes before the system would have.

[spoon059]

SoundGuy wrote:

What's the point when the vehicle's lighting switch allows you to simply turn the lights on? :h

I like to have my lights on all the time when driving. To make it easier, I put a piece of tape over the sensor on the dash and turn the lights to auto. That way the truck thinks its always night and turns on the lights as soon as the truck is on and off as soon as the truck is off.

[ktmrfs]

Chad/Jen wrote:
When bringing my trailer home over the weekend I noticed that the lights to my truck ('14 Chevy Silverado) were on (not just the DRLs but the actual headlights and taillights). I have the light switch set to "Auto" so I don't have to worry about them. I noticed when I looked in the mirror that the marker lights for the trailer weren't on. I think (but don't remember for sure) that in the past the lights for the trailer have come on when the ones for the truck did, even with the "Auto" setting on. I turned the knob to turn the lights on the old fashioned way and the ones for the trailer came on. Shouldn't the lights for the trailer be when the truck's are, even if the truck's selector is on Auto, or am I missing something?

on my 04.5 the trailer running lights only come on when the headlights are ON. not when just DRL are on. trailer running lights are hooked to the headlight circuit on the TV. So, in Auto mode if all that is on is the DRL, then the trailer running lights won't be on. when the truck headlights come on the trailer running lights should come on.

That's the way my 04.5 worked and my 2015.5 duramax as well.