Here's a link which shows the different types of wiring. In the middle, is the wiring for a 7-wire cord such as you have. It's pretty self-explanatory.
http://www.offroaders.com/tech/trail...ng-diagram.htm.
Here's a link which should help you with the breakaway switch.
http://www.ehow.com/how_5001900_wire...ay-switch.html.
Be sure to make sure there are no cuts in the wire's cover as those will allow water in and your wiring will corrode quickly. If possible, it's worthwhile to solder each joint and then use shrink tubing to seal it up. There is also a very nice liquid rubber you can get to paint each connection with that will make them waterproof.