1-2-both switch between starter and trolling

[plasticfailure]

i think this should be an easy answer. I've got two 12V batts. in parallel for my trolling motor. I'd like to have a switch so that I can start the main motor if my starting battery fails. The switch i have is a Perko, all it has is places to connect the positive wires. So my question is, do i just need to jumper the negative terminals between my batteries so that all my accessories and stuff from my main batter will be grounded to the other batteries wheni I switch it that way? I can't figure any other way that it could work.

 

[dingbat]

Re: 1-2-both switch between starter and trolling

The grounds on my batteries are in series.

 

[18rabbit]

Re: 1-2-both switch between starter and trolling

The ground is common (shared) for all of your batteries. Yes, connect the grounds of the two battery banks.

 

[kalan2000]

Re: 1-2-both switch between starter and trolling

I'm assuming your TM batts hardwired in parallel. If so, connect the grounds and wire the hot from the TM bank thru the switch to the #2 position, with the start batt on #1. If you need all 3 to start, set switch to 'all' to crank with all 3.