I recently bought a 2016 Africa Twin that came with OEM heated grips. Unfortunately, the switch on the left grip was broken when I bought it. The switch functions, but the two halves of the plastic switch housing would not clip together. Today, the top half of the plastic housing (the one with the button)disappeared during a ride. Can I replace just the switch or plastic housing, or do I have to buy the entire grip set for $150+?