If you want to do some detective work, you can probably get a replacement quickly and at lower cost. You need to remove the switch, making a wiring diagram and marking wires to enable you to get it back together. I would disconnect the battery red wires before doing this. From the function, I would bet that it is a double pole double throw (DPDT) switch, which has 6 terminals. Note the DC amps rating and any numbers printed on it. Take it to a good auto parts store, and they can probably match it, or Google the marking numbers to identify it and find a replacement source.