2021 Sierra Trailer Reverse LED Lights Turn On then Off

[OrdO2110]

Ok I use the light test on the truck and the reverse lights on my trailer turn on then off after about 1-2 seconds. When I place the truck in reverse same thing. I have 4 tiny LED reverse lights and 1 18" LED light bar on the back of my trailer. I have tried using adapters that have resistance. Trailer came with 4 wire plug, I made it a 5 wire plug to have reverse lights on the trailer. Worked fine on my 2013 Suburban. No fuse is blown as they go on then right back off after 1-2 seconds. Trailer is all LED lights and every other light function on it works. Any help is appreciated.

 

2021 Sierra 1500 AT4 Carbon Pro with everything.

2021 Trailer singe axle 6'x12'.

[calgator73]

3 minutes ago, OrdO2110 said:

Ok I use the light test on the truck and the reverse lights on my trailer turn on then off after about 1-2 seconds. When I place the truck in reverse same thing. I have 4 tiny LED reverse lights and 1 18" LED light bar on the back of my trailer. I have tried using adapters that have resistance. Trailer came with 4 wire plug, I made it a 5 wire plug to have reverse lights on the trailer. Worked fine on my 2013 Suburban. No fuse is blown as they go on then right back off after 1-2 seconds. Trailer is all LED lights and every other light function on it works. Any help is appreciated.

 

2021 Sierra 1500 AT4 Carbon Pro with everything.

2021 Trailer singe axle 6'x12'.

Might be too much current draw and the BCM is protecting the circuit.  Try bypassing the 18" bar and see if it improves.  If it does you might need to put a relay so it draws off your breakaway battery when in reverse.

[OrdO2110]

Thank you. I will try to mess with it this weekend and try that.

[OrdO2110]

Thanks @calgator73 that was the issue! Can't believe it will not keep it on, hardly any power for the bigger LED light. Now I need to figure out how to add maybe a small battery to the trailer to connect it to with a relay that will charge the battery also. Trailer is single axle with no electric brakes.

 

[calgator73]

1 hour ago, OrdO2110 said:

Thanks @calgator73 that was the issue! Can't believe it will not keep it on, hardly any power for the bigger LED light. Now I need to figure out how to add maybe a small battery to the trailer to connect it to with a relay that will charge the battery also. Trailer is single axle with no electric brakes.

 

Glad it's working for you.  An 18" led can draw 12 or more amps...pretty substantial. Use this schematic to determine your pin out and this other one to help you wire the relay.

 

Battery will charge via pin 4.  The relay control from pin 7 to pin 86 with pin 85 to ground.

 

Battery will connect to relay pin 30 using 10 gauge wire.  Pin 87 connects to all reverse lights via 10 gauge as well although it's only important to the light bar.

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[OrdO2110]

@calgator73 That worked also! Thanks for the help. Guess I am learning these new vehicles can't be wired the way they used to be. Appreciate all the help.

[calgator73]

1 hour ago, OrdO2110 said:

@calgator73 That worked also! Thanks for the help. Guess I am learning these new vehicles can't be wired the way they used to be. Appreciate all the help.

No problem.  Take care