[zlssefi]

Today i had my truck outfitted with a 9 foot boss dxt snow plow. Like all of my previous trucks i asked to have two led work lights added in on the reverse lighting circuit. The installer told me that the truck " didnt like them" and the truck would shut the circuit down after about 10 seconds in reverse. I do know that they tapped the trailer plug reverse circuit not the truck tail light reverse circuit. Does anyone have any experience like this on the new trucks and what was the workaround to making these lights work??

 

[Mrchase]

Following

 

[cwren2472]

What he said might be correct if he had spliced into the truck reverse light but if he's going off the trailer plug, there's no reason it shouldn't work

 

[zlssefi]

They are saying the opposite. They tapped off of the trailer plug circuit, not the actual truck lights. When the aux lights shut off the truck lights stayed on, almost like the BCM shut the trailer circuit down. Today im going to pull one of the stock reverse bulbs and temp wire the aux light from there to see if they stay on.

 

[cwren2472]

I cant say I recall trying that exact truck - maybe ill have to try it next time we get a new Chevy in. But I can't see any reason it wouldn't work, sort of trying to use obnoxiously powerful lights drawing more than the circuit was rated for.

 

[zlssefi]

I cant say I recall trying that exact truck - maybe ill have to try it next time we get a new Chevy in. But I can't see any reason it wouldn't work, sort of trying to use obnoxiously powerful lights drawing more than the circuit was rated for.

Let me know what you find. The stock lights are incandescent and generally leds hardly draw anything but i guess its a possibility.

 

[Kevin_NJ]

MAYBE they are using an isolated/dedicated ground for the trailer circuit now? If they only tapped into the hot from the trailer harness and not the ground also, that made the computer upset?

 

[Kevin_NJ]

Found this in the upfitter manual. That was another thought I had, the computer knows if there is a trailer there or not. Page 2-51. https://www.gmupfitter.com/wp-conte...lectrical_Body_Builder_SM_en_US_2022OCT12.pdf

 

[cwren2472]

MAYBE they are using an isolated/dedicated ground for the trailer circuit now? If they only tapped into the hot from the trailer harness and not the ground also, that made the computer upset?

Could be? Some of the truck computers now look for specific circuits (aux. battery, brakes, etc.) to be connected in order to decide if a trailer is "present" to make things live - it could be that truck doesn't like having only 1 circuit on the trailer plug being used. I've never encountered that on a chevy, only on Fords, and even then it never affected the reverse lights. But anything is possible.

 

[Philbilly2]

MAYBE they are using an isolated/dedicated ground for the trailer circuit now? If they only tapped into the hot from the trailer harness and not the ground also, that made the computer upset?

I think this is the reason.

When you plug in a trailer the truck knows you plugged in a wagon and loads the trailering app on the screen and asks you which trailer you are hooking up to so it can set the brake gain, track the milage interval for service, turns on the side trailer view screen with the directionals. bunch of other stuff I have not figured out yet.

PSA... If you have your truck shut off and locked and you pull the trailer plug out to get it unhooked you set off the truck alarm cause it thinks someone is stealing your wagon. (I noah guy 😬)

Lots of unnecessary garbage on these new trucks

 

[zlssefi]

All great stuff. Ill dig in today.

 

[cwren2472]

PSA... If you have your truck shut off and locked and you pull the trailer plug out to get it unhooked you set off the truck alarm cause it thinks someone is stealing your wagon. (I noah guy 😬)

Normally I hate unnecessary complications like that and truck computers trying to outsmart you, but in this case that actually seems kinda cool

 

[Philbilly2]

Normally I hate unnecessary complications like that and truck computers trying to outsmart you, but in this case that actually seems kinda cool

Yeah... in the parking lot of a little motel at about 5:45am when the key was not in my pocket...

I can assure you it was not in fact "cool"

 

[cwren2472]

Yeah... in the parking lot of a little motel at about 5:45am when the key was not in my pocket...

I can assure you it was not in fact "cool"

Sounds like you are mad because you got caught stealing a trailer. Crime doesn't pay you know

 

[Mountain Bob]

Gonna play captain obvious here, I'd try using a relay, preferably a low draw quality one, like a Bosch, have the reverse lights on truck only turn on the relay, the truck module may not notice such a slight difference, and get power from somewhere else for the lights. At worse you might have to run a wire forward. Heck, it would only take a few minutes to temporarily wire a relay up and test this.

 

[TJS]

Too add to Mtn Bob suggestion:
Got to Hoppy's website. The Center of the large trailer standard trailer connectors I think is the 12+ charging wire.Dont take my word for it go there for a diagram. You can tap the relay off of that for the #30 feed in (might want to fuse it). I have a relay set up on my old school no module ford for my beeper and extra reverse lights. I have a switch in my truck where I pull the ground away from the beeeper when I dont want it to beep.

 

[Philbilly2]

Too add to Mtn Bob suggestion:
Got to Hoppy's website. The Center of the large trailer standard trailer connectors I think is the 12+ charging wire.Dont take my word for it go there for a diagram. You can tap the relay off of that for the #30 feed in (might want to fuse it). I have a relay set up on my old school no module ford for my beeper and extra reverse lights. I have a switch in my truck where I pull the ground away from the beeeper when I dont want it to beep.

Center is reverse lights. 12v+ is the upper right if I recall correct. But I am sure the center is backup lights

 

[FlakePusher]

Use the trailer charge wire to feed the higher current side of a relay (pin 30)and be sure to fuse it properly according to feed wire size that you use . Run a relay with a flyback diode or resistor. Tap the trailer reverse wire to trigger the relay (pin 86). pin 85 is ground, pin 87 will feed your back-up lights. get quality lights in diffused or flood. I really like these Aurora lights. Make sure the relay is either tucked up high in a tail light pocket away from elements or make sure to use a weather proof version so no pins are exposed to the elements.

 

[zlssefi]

Problem solved. I decided to pull out a truckside reverse bulb and temp wire the led light to it. It stayed on as long as the truck was in reverse. Moral of the story is to not over think things!!