good info here also

http://www.marinco.com/page/wire-tech-data

The stock mercury trim harness has a pair of bullet connectors in the back to connect to the trim limit. Then it has an additional wire for the trailer switch. Are you going to re-use the stock harness?

Im going to order one of the replacement main harnesses, a replacement trim harnes and then run the rest new.

Sounds like a plan

There are a few ways you can wire the trim limit switch. If bet if you google "mercury wire harness diagram" you will get plenty of them. Another thing to think about is your battery and what accessories you may want to be powered at all times. Thinks like trim is nice to have hooked up directly to the battery on outboard because I can just reach up and trim the motor from the ground. The bilge pumps of course NEED to be on constant power. If you are calculating what gauge wire you need to run, remember with DC it is the entire length of the run up and back. So if you have a 2 conductor wire that is 10 feet then you should calculate your power loss at 20 feet.

I have attached the Coast Guard chart for wire sizing. I find it to be a little overkill but it is a good reference.

Jon

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