Wiring up two batteries and switch

[foxtrot]

Ok I have a battery selector switch. It has batt #1, batt #2, 1+2, And off. I want to change my trolling motor battery (batt #2) to a bow position but my wiring terminal is in the stern. I want to know if I can just wire the positive to the switch, then to the accessory terminal then I could run the ground from the accessory terminal to the negative post on my starting battery(batt #1). Or would I have to wire the ground to my trolling motor battery.

 

[kofkorn]

I'm not exactly sure what you are trying to say, but from my reading if you go:

12v (+) -> switch -> accessory terminal -> to Ground

then you've created a dead short.

if you mean:

12v (+) -> Circuit Breaker -> switch -> accessory terminal -> TM Pos Lead

Then

TM Neg Lead -> Separate Accessory Terminal -> 12V (-)

you should be ok. The thing to watch will be to add up all of the wire length (pos & neg sides) and use a wire Gauge chart to determine your minimum wire gauge. That's what you're going to need for ALL connections. Additionally, you should wire a circuit breaker between the 12V(+) and the switch. Also, your accessory terminals need to be rated to handle the full TM load (Likely between 50A and 60A.

Good luck!

 

[foxtrot]

Ok on battery 2 I wanted to go positive batt2->switch->terminal bus.
Then negative batt 1 -> terminal bus.

Basically I was trying to avoid running two wires under the decking to hook up the ground to the negative terminal bus.

 

[kofkorn]

You're going to have to draw this up, because I still don't get what you're trying to do. You certainly don't want to hook your B2(+) to the same wiring bus that you have B2(-) attached to. That is going to do one of two things depending on the remainder of B2 wiring:

1) it will supply 24V to the trolling motor which will burn it up if it's not a 12/24V motor
or,
2) it creates a short between B2(+) and ground which will likely cause a battery meltdown.

the only way to move your motor to the front without two wires would be to use your boat hull as the ground. This tends to cause problems with electrolysis and is not advisable.

I would advise that you run the extra wire.

Good luck!

 

[foxtrot]

I ended up just running the wires.