LED Rear Bumper Lights

[fluxcapacitor11]

Just installed an aftermarket rear bumper, came with some LED cubes.  I figured I would run the wiring up to the lights in the bed.  It’s a short run, and would be able to turn on with the factory cargo light button (I did the same thing for my led fog lights on the front bumper, just use factory fog light button).  For some reason this will not work now.  Push the button, and the lights flash 3 times and won’t come back on until I reset the button. Tried with a relay (came with lights), tried without, tried a different ground…nothing will work.  Any ideas out there?  Other than “run it to battery”.  
 

thanks in advance 

[GETGONE]

Where are you powering the relay from? You have to use the trigger for the relay from the cargo and/or reverse lights and I got the power from the trailer harness for the 12V+  When you overload the circuit that is what causes the flashing.

[fluxcapacitor11]

7 hours ago, GETGONE said:

Where are you powering the relay from? You have to use the trigger for the relay from the cargo and/or reverse lights and I got the power from the trailer harness for the 12V+  When you overload the circuit that is what causes the flashing.

The harness that came with the lights is just a red and black on the relay, and an on/off button.   I was wiring 12v at the lights to + on harness, and ground to - on harness.  I know nothing about relays/triggers.  

[GETGONE]

https://www.gm-trucks.com/forums/topic/251499-2021-sierra-wiring-led-backup-lightselectrical-experts-needed/page/2/#comment-2562451