I don't know the circuit for your truck, and I'm not sitting in front of my truck or a schematic, but a heavier gauge won't hurt. 10 is a little big, though, do you have extra or something?

I found the wiring diagram for your truck , and it says one side is grounded the other hot, so its a variable resister device. 10 gauge might alter your final reading, but I'd just try it and add some resistance later if needed. Or you could just spend a buck and use 18ga.

Dave