With regard to the wiring; I used two relays in parallel and a feed spliced into the stock backup lights to power one of the relays when the Jeep is put in reverse.
The other relay is connected to a switch and turns them on when the switch is thrown.
With the relays in parallel with the power supply for the lights (but two different sources powering the two relays) the backup lights will light when either relay is activated by either the backup lights coming on or the switch being thrown. Basically, they way I did it , it behaves as two separate relay switched circuits. One is operated by a toggle and the other is operated when you put your Jeep in reverse - they just happen to turn on the same thing.
My splice was done on the wiring harness near the rear passenger side backup light. The wire bundle can be accessed behind the passenger side plastic panel in the cargo area. I just used a multi-meter to ID the correct wire that had power when the vehicle was in reverse and the backup light was the only one lit. This is where I spliced in the wire to power the relay. The drain from the relay is minimal and should not affect anything else.
No diode needed or worry about power going the wrong way...or a diode breaking down at wrong time... ;')
Also it won't matter if you put the vehicle in reverse when the switch is thrown as it will just complete the power to the lights circuit in two places.
Click the thumbnail to enlarge the wiring diagram.
I went back and reread my original post in my Mods thread and realized it was not very clear. I have updated it to reflect this post.
John
];')