Snow plow headlight switch

Assumption - this is a standard toggle switch, not something like a rotary switch.

If the assumption is correct, you could use a standard DPDT toggle; Radio Shack # 275-710 would work, but you could see if you could find one that's two position, without the center off position. If the radio shack switch was used, know that 'center off' position would result in no headlights at all.

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F015%5F001&product%5fid=275%2D710

Current draw is limited to 20 amps, perhaps you could use relays to help.

Jim