Postby mar1 » Fri Jan 04, 2013 2:25 pm
first of all you will need a sensor to know when the trailer is attached and when it isnt. it can be just an ordinary on/off switch.
you will also need a plug that you connect/disconnect whenever the trailer is used. thats just aesthetics and you shouldnt have an issue with that.
the sensor should be installed to a relay input control. the 2 display inputs of the relay will be the default camera and the trailer camera.
depending on the relay wiring, you can set one input as default on, and the second input will be triggered once the sensor receives a positive signal (once trailer is connected)
the output of the relay should be connected to the default reverse wire screen input. i.e. where the already existing camera is connected.
the 12V can be taken from anywhere. you should have a 12V power socket in the rear.