Underdash electrical wiring info?

[bandera]

I'm getting ready to add some aux back-up lights and some other things and need to find out if anyone knows which wire under the dash I need to hook into for the back-up lights so I can hook it up to activate a relay.  The other I'm looking for is which is a good wire to hook into that is hot only when the switch in the "ON" or "ACCESSORY" position to activate a relay only when the key is ON.  Have not even started yet, but thought if anybody out there has done this and know which ones I need, it sure would save me alot of time and trouble.  Thanks

[99silveradoz71]

Jason Pendlum would be a good contact for it as he has wiring diagrams done out for reverse lights that a shop that did my install used.