I did that
I have a Y2K 3500,I have J&J lighted stainless running boards.
The lights are amber except for one under each front door that is
clear(frosted).
I hooked into the pink wire coming off the back of the headlight switch. These two lights now work with the dome and map lights.
They come on when disarming and unlocking with remote,go out when arming with remote,on with doors open. Would guess that
you wire would be same color.
As near as I could figure,had to tap in at the headlight switch,so they would retain all the functions. I tried the wire to the doorjamb
switch. . only worked with door opening. Hope this helps.
Fuzz