KBX500

I'm hoping that one of you can help me with wiring the interior light of the truck
cap on a 2003 S-10. The shell is the Impulse made by A.R.E., also made about
2003.
The wiring in the cap is is simple, just 2 wires. A red power wire and black ground.
The ground is easy of course, with a factory grounding point on the left rear frame
rail. My concern is the best place to connect the power wire. I found the single blue
wire for the 3rd brake light that Chevy provides, but haven't found the wire for the
cap interior light. Is there a factory supplied power wire for it ?
If not what the best place to take power from ? Something that is fused.
Also, do 2003 S-10s have a LCM (Lighting Control Module) ?
So many vehicles do and I don't want to fry it by tapping into the wrong place.

Thanks in advance for your help.
KBX500