Originally Posted by
timsrv
Sounds like BS to me. I could be wrong, but I'm not aware of any such switch. Does the fan work for heat? If the fan doesn't work at all, then I'd check the circuit breaker 1st then I'd check for power at the fan motor. If there's power to the motor and it's not turning, then you have a bad motor. If the motor doesn't have power, then I'd track the circuit back-wards. Other likely causes of failure could be the heater relay or the fan switch on the dash. There's also the blower resistor, but if that failed it would still work on high. I need to go on a job right now so there's no time to review schematics or post pics. I'll come back later tonight or tomorrow and give you a more thorough response. Tim