The passenger side seat heater in my 244 doesn't work. The lighted switch between the seats that activates it lights up when I turn it on, but the seat doesn't get hot. There's a small part missing from the opaque plastic part of the switch, but I wouldn't think that would cause the heater not to work. The driver side heater works fine, which is what I really care about, but if the fix is simple, I'd like to give a shot at repairing the passenger side heater too. What do I need to check/do?