Unidentified Knob...

[beaker152]

looks like a bosch logo.

my guess would be for spotties. do you have aux. lights on it?

have you pulled/pushed it?

chase the wires, it's the only way to know for sure.

hth's
crusty

no lights, but i think you called it...

tried googling to find the switch with no joy, but i'm glad to know it's an aftermarket thing...

-steve

ps. oh, and here's the bosch logo--looks like a match to me

 

[crushers]

i have the exact same switch on my Mits jeep, it cuts all the power to the truck. in my case it was used for periods of long inactivity to prevent draining the battery.
it is just a big assed toggle switch...