Why are two speeds on my fan not working?
The most common cause of two or more speeds not working is the resistor, because if resistor two burns out it will affect speeds 1 and 2 but not 3 and 4. Here is a typical wiring Diagram, this one does not use a separate circuit and relay for high.
How is the speed of a 2 wire fan controlled?
A 2-wire fan is controlled by adjusting either the dc voltage or pulse width in low-frequency PWM. However, with only two wires, a tach signal is not readily available. This means that there is no indication as to how fast the fan is running—or indeed, if it is running at all. This form of speed control is open-loop.
Why does my dashboard fan not turn on?
The green tracing is low, and goes through all three resistors The blue tracing is med low, and goes through resistor 2 and 3 The red tracing is med high, and goes through resistor 3 only. If Resistor two is blow it will prevent green and blue circuits from working.
What to do if your blower fan is not working?
You need a new resistor block, or just the thermal fuse. For this car you need a 192°C, 250V, 10A thermal fuse. If you have the same problem on your Vw Golf 4 / Bora / Skoda Octavia 1, the repairing method is similar. You need to dismantle the dashboard to reach the blower fan and fan resistor. If you enjoyed this tutorial, please subscribe!
The most common cause of two or more speeds not working is the resistor, because if resistor two burns out it will affect speeds 1 and 2 but not 3 and 4. Here is a typical wiring Diagram, this one does not use a separate circuit and relay for high.
A 2-wire fan is controlled by adjusting either the dc voltage or pulse width in low-frequency PWM. However, with only two wires, a tach signal is not readily available. This means that there is no indication as to how fast the fan is running—or indeed, if it is running at all. This form of speed control is open-loop.
The green tracing is low, and goes through all three resistors The blue tracing is med low, and goes through resistor 2 and 3 The red tracing is med high, and goes through resistor 3 only. If Resistor two is blow it will prevent green and blue circuits from working.
You need a new resistor block, or just the thermal fuse. For this car you need a 192°C, 250V, 10A thermal fuse. If you have the same problem on your Vw Golf 4 / Bora / Skoda Octavia 1, the repairing method is similar. You need to dismantle the dashboard to reach the blower fan and fan resistor. If you enjoyed this tutorial, please subscribe!