Since the computer on my truck died that left me with two switches on the steering wheel for the cruise control that doesn't work.

I want to know if there is a way that I can use the on/off rocker as an interupter for the ground on the overdrive.

The other momentary 3way would be cool for volume on my radio.

How do I find where these wires come out?

 

you should be able with some relays.

The on/off switch should be fine.

The resume button gives contact when you press on it.
The set button removes contact when you press on it.

When ON, it gives power to the SET and RESUME switches. I can send you a wiring diagram if you want.

Remove the lower plastic cover from your column (the one closer to the steering) and you will see the connector coming out of the clockspring with 5 wires (1 for horn, 4 going to switches)