I've got about $50 out on the mirror and temp. probe for my truck. Temp. probe is in plcace and wires run into the cab. Questions are:

How do I route the wires up the windshield pillar?

Were should I grab the power from?

Should I fuse it? What amp (2?)

 

Pull the A-pillar trim, pull the wires, and snap the trim back into place. You can just tuck the wires into the front of the headliner.

Tapping the fused circuit that the factory uses for that option is the best way. You might even be able to find the connector that the factory provides on your dash harness to hook into. If it doesn't exist, splice into the radio's switched circuit.

I do this to all my vehicles, my g/f's, & many of my friends' & family's vehicles.