25-10-15, 11:12 PM
I had this issue and it was the sensor rather than the drive dog (bit that spins in the wheel). I had a small split right at the base of the wire and moisture was getting in there and causing chaos. You could try sealing it up if you have a split with amalgamating tape or something as the sensors are about £130 new and rare as rocking horse shit to get second hand. Check the drive first though, easy fix if thats broken and about £16.