the thermo is also there.
The switch is for the cases that
1. will clim a steeeeeeeeeeeeeeep hill that will overhet the engine ( preventive )
2. when crossing a river you dont want the fan to be on since it will splash the hole engine electriks or brake its fins. Any way been in the water it will cool the engine down

'96 4d mechanicaly stock so far, rims, spoiler, Cooper AT tyres, Factory LSD, Manual Warn Hubs, handmade exaust, ELECTRIC FAN!!! 3,1'' Lift, PALM GPS