[Qmulus]

Originally Posted by j.fro

Has anyone wired in a switch to manually operate the radiator fans? I've pulled the AC, so I can't operate that way. In grid, my car gets a bit hot and I'd like to turn the fans on much earlier than 220 or whatever temp is automatic.
I tried jumping from the relays, but no luck.

I have done wiring on a bunch of Boxsters and 911s of various years. Most remove the fans completely to get better cooling without the restriction that the fans add when they are not running. That said, I was also asked to add in fan wiring in a 997 race car that did not originally have fans for the reason you are mentioning.

What you are looking for would be a pretty simple change. I assume that you would want just high speed to bring down temps quickly and you have the original wiring in the car? All you have to do is install a SPST on/on switch in series with the small yellow/gray trigger wire from the DME to the high speed fan relays. In a convenient place cut the yellow/gray wire from DME to the high speed fan relays and extend what are now two wires to wherever you want the switch. Connect the wire that goes to the high speed fan relays to the center terminal of the switch. Connect the wire from the DME to the top terminal on the switch. Connect the bottom terminal on the switch to ground. When the switch is down, the high speed fans will work as normal controlled by the DME. When the switch is in the up position you will manually turn on the fans. You could do the same with the low speed by interrupting the yellow/green wire to the low speed fans.

HTH!