Yes, it's a very simple positive/negative switch...just make sure you give the wire plenty of slack (and that it won't get caught on anything). That little rubber plug wire onthe differential is a pain in the *** to fix, and expensive to replace.
I would put a relay in the circuit. That is 4 amps cold on the bench, how many amps is it hot?
Not just amps - but a toggle simply shouldn't be expected to handle the arc of the connect and disconnect - over time the toggle's contacts will burnish and carbonize... the reduced risk of failure on the trail (and we all know stuff somehow knows exactly when to fail causing the most problems) justifies the cost of the relay.
J Wm Bishop EA, ASADE
Waiting for the JAMBOREE at Rubicon is worse than waiting for Christmas...