Quick Wiring Question
 

So I'm wiring up my oil press. gauge and I want to splice a wire for the backlighting. I figured I'd use the climate control wires because I'm mounting my gauge right above that, and want to have the gauge light come on when they are lit. Which wire should I splice into? The FSM's wiring diagrams aren't being too helpful and I don't have a Chilton/Haynes.
Thanks

red/blue is the 12v+ for lighting.

okay thank you.