I'm kinda new to this, but i bought fog lights and a switch for my 71 914. The car didn't come with fog lights when I bought it. I just need to know what the #31, 15, and K mean on the switch and maybe a quick explanation on how to hook it up please. Thanks for your help.

do you have a multi meter [volt/ohms meter] ?

Yeah I have multi-meter

if this is a lighted switch... one will be power from the relay, one will be grnd, and the last will be to the lights.

look here http://www.bcae1.com/switches.htm

or

15 = Positive feed
K = from switch to relay #86 (relay trigger)
31 = Wire to ground

Thanks a lot you guys, happy New Years

http://en.wikipedia.org/wiki/DIN_72552

The power to "15" comes from the low beam side of the headlight switch or headlight relay.

The Cap'n