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[iCruiser]

I recently installed some backup lights so maybe I can help.

First kokopelli's comments are right on the money!

The way I did it.
1.ran power from my battery through the firewall and along the driver's door sill until it ended up in the rear access door (one with tools). I also ran a signal wire to trip the relay along side the power wire.

2. connected the lights and grounded them within the rear hatch and hooked the wires up as stated by kokopelli.

3. up front I used a oem rocker switch with led indicator.

4. ran a tap from the reverse wire (forgot what color/will look up) that's located laterally to the driver's fuse box, and connected it to the switch, also connected ground and signal wire (that runs to the relay)

So now if I have the switch ON, when reversing, the rear lights turn on and the inicator led is lit (on the switch)

If you want light on demand and not only when reversing, the power switch needs to connect to a constant 12V.

If you want both the luxury of on demand and when reversing, etc.. that wiring is a bit more complicated.

good luck!
hope that helps a bit.

T