Bilge Switch - should I switch positive or negative?

[E350]

 

[kevbo]

Is a chaffed wire more likely to find a positive or negative source to short against? If the entire engine and exhaust is negative I would fuse/switch the positive wire.

 

[mikesx]

Always break the positive with the switch, especially with pumps sitting in a wet bilge. If you break the ground with the switch a failing/leaking ( into the pump) pump would ground your batt. Pump wouldn’t be running, you wouldn’t hear anything, your first indication of a problem would be a dead batt.
Failing pumps = silent battery killers, lol

 

[mikesx]

Here’s how I wire all my bilges. I use plugs for quick troubleshooting. Fuse the positive. First pic. Second pic, the plugs are right to left:
1st plug, Battery pos fuse , neg
2nd plug, one side of plug up to switch other side of plug neg pass thru to 3rd plug
3rd plug, other side of switch coming back
4th plug, 2 wires to pump.
If I push switch and pump doesn’t run I can plug 1st plug into 4th for quick troubleshooting.

 

[Roseand]

Heres how i set it up using the wax harness. Fuse the positive.

 

[E350]

@kevbo @mikesx @Roseand Thank you all.

I used the @waxhead wiring harness, then used heat shrink heat soldering butt connectors to attach it to the Blowsion handlebar switch and 4A fused the positive lead to the switch.

It is working great.

Thanks again to all.