I am running the 6 volt switch with a 12 volt motor on a 12 volt system on my '49 1/2 ton. Switch gets a bit over warm in the low and medium position after 2 hours of running, but not hot. I'm with dgrinnan and 52Carl on this one....so far.

Tim

"Pay attention to the details! It ALWAYS pays off."

1949 Chevrolet 3100 Series 1/2 ton Pickup
1964 Chevrolet C10 (Ol' Yella) (SOLD)
1958 Chevrolet Biscayne 2 door (SOLD)
1970 VW Beetle