Spal Fan Controller Setup
Ok, I got the handlebar switch mounted. Turns out my Vapor computer won't run properly off the AC wire either (false and sporadic tachometer readings resulted). So I now have the Vapor and the fan controller running off DC. Neither take much juice to run. The controller takes only 0.2 amps to function.
Not a particularly cheap route to go, the way I have it. But, here's what I've got into it:
Vapor computer ~$80
Additional temp sensor (replaces the air bleed screw on the head for the cooling system)~$40.
Factory Fan kit ~$135
Spal fan controller ~$80
Handlebar switch ~$16
Note: You're supposed to be able to splice into almost any existing temp sensor to work with the fan controller. I tried it with the in-line hose mount sensor that comes with the Vapor, but the controller didn't play nice with the shared sensor. Thus, the additional sensor.
Another note: You can save a grip a cash if you just buy the fan only from Spal, instead of the fan kit from KTM. If you're running a 2005 'berg the thermo switch that comes with the fan kit won't thread into the radiator (cause there's no threaded collar in it). That makes it, and the other wire harnes that comes with the kit useless. The only other useful part of the kit (other than the fan) are the mounts.
Anyway, I have the controller set to turn on the fan at slow speed (50%) at about 190 degrees C and the high speed (100%) at about 235. Whether there is actually any difference in fan speed between the two settings (as LeFrog suggests) I haven't yet determined.
Here's some pics: