OK, I have a question. Can I tap into the wires for my bow trim controls to wire my fish finder at the bow? I really don't want to run wires all the way back to the cranking battery if I can help it. I haven't bought a fish finder yet, I'm just doing some research. If I can use the trim control wires, I'm guessing I can pigtail the hot and the ground? Thanks for any help here.

There is no ground wire on the trim switch. The switch distributes the positive side of the circuit to each trim soleniod just like a light switch on your house. 

 

If you get a simple sonar unit with mininum power requirements, yes you can use the boat wiring harness.

A unit with GPS, 2D sonar, and the imaging technology has a higher amp usage and typically the resistance in the boat wiring harness cannot support those units. 

There is no ground wire on the trim switch. The switch distributes the positive side of the circuit to each trim soleniod just like a light switch on your house. 

 

If you get a simple sonar unit with mininum power requirements, yes you can use the boat wiring harness.

A unit with GPS, 2D sonar, and the imaging technology has a higher amp usage and typically the resistance in the boat wiring harness cannot support those units. 

 

Thanks for the info, I've decided I just need to mount my one fish finder with a ram type mount so I can swivel it to view it when I'm at the bow. Now to figure out what's involved with that.