as said above, but before going to that extreme, just try turning it off at the switch, or even better pull out the fuse at the fuse box for 5 mins...most of these seem to then reset themselves when you turn the power back on...then its amatter of turning the switch on and off again...sometimes the diffeerent modes eg on permanantly, or sensor mode is determined by how fast you turn the switch on and off.
mark, March 2010