[mavrick0]

Yes the in cab would be simple as the use of a pico switch. What a pico switch does is plugs into one of your channels in your RX that is controlled by a switch on the TX. As for the trailer the only way I could see it being the simplest is using the micro switch to turn them on and off when you are hooked up or disconnected from the trailer.

Using different trailers isn't an issue. You just need to pair the Master OB1 to the Slave OB1 and you are good to go. It's not that hard to do or takes very long. The micro switch is mounted into the plate of the trailer that the 5th wheel rides on. You just need to make sure it make contact throughout the full motion of the 5th wheel as the tractor turns. All you need to do is wire it like an on/off switch between your power supply and the lights.

I love my ss-tronix. I'm glad I have an extra couple of kits since they aren't making them at the moment if at all. I do have their landing gear controllers as well and work great.