2016 - how to wire up truck cap / topper lights.

On my new truck (2016 Ram 2500 crew cab, short bed, 4x4) I'm installing a construction cap with LED lights on the inside. I didn't find anything on the http://rambodybuilder.com/ website for how to upfit for the interior lights. I did find where they hid the wire for the high mount brake light.

So, I emailed them about what they recommend and here it is. Hopefully it will be helpful to someone else. I plan on using it to power a relay and using the existing rear battery power as the supply:

From RAM:
We do not offer an output specifically for you to tie into. That feed for those lights is not a relay driven feed. It is a solid state driver in the CBC and is only capable of about 2.2 amps. That should be sufficient for LEDs. The problem is, these are big LEDs and the inrush current is high. You could splice into the lighting circuit. If the lights quit working, you have over loaded the driver and the computer has shut the output down. That’s not a problem, just disconnect the extra load and the output will come back on the next key cycle. If your added lighting is too much, you could try adding a relay. If it’s still too much, try a solid state relay.