- Faulty fan switch: The fan switch itself may be faulty, preventing it from sending a signal to the fan to turn on at lower speeds.
- Blown fuse: The fuse for the fan may have blown, interrupting the power supply to the fan switch and fan.
- Wiring issue: There may be a break in the wiring between the fan switch and the fan, preventing the fan from receiving the signal to turn on.
- Faulty fan relay: The fan relay, which controls the power supply to the fan, may be faulty, preventing the fan from turning on at lower speeds.
- Faulty fan motor: The fan motor itself may be faulty, preventing it from responding to the signals from the fan switch.
To troubleshoot the issue, you can start by checking the fuse for the fan and replacing it if necessary. Next, inspect the wiring between the fan switch and the fan for any breaks or damage. If the wiring appears to be intact, you can try replacing the fan switch and the fan relay one by one to see if that resolves the problem. If the fan still only works on high after trying these steps, it is likely that the fan motor itself is faulty and will need to be replaced.
