Which wire for lights?

[raunch]

For the lights in my new temp gauge, I need to tap into a wire under my dash to turn the tempgauge light on with the rest. My Chilton's manual says that out of the light switch I could hook into the parking lights (brown wire) or the gauge lights (green). All the wires out of my light switch are white. Which wire in the rat's nest under the dash could I tap into?
Thanks.

[DmaxMaverick]

Locate the output wire off of the rheostat. Use a VOM or test lamp to probe the wires. The dimmer circuit (same as for IPC lamps) will vary voltage (or dim your test lamp) as the knob is turned. With this, your gage lighting will dim with the dash lights. If you use the parking lamp circuit, your gage lamp will be full-bright all the time. Most of the time, it's too bright (distracting at night), and the bulb won't last long.

[raunch]

Good point. Didn't think of that gauge shining in my eyes.
Thanks.