Fan resistors are used to control the fan speed in an automobile supercharger. The change in resistance affects the amount of current in the motor's electrical circuit, which in turn controls the fan speed in the supercharger. Fan resistors are mechanical components and are therefore subject to wear and tear, which is the cause of most problems in a vehicle's heating system.

1. TRANSPORTER IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7DC, 7DJ)
2. TRANSPORTER / CARAVELLE IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K
3. TRANSPORTER / MULTIVAN IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K,
4. EUROVAN / CARAVELLE IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7D
5. TRANSPORTER T4 Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7DC, 7DJ)
6. TRANSPORTER / CARAVELLE Mk IV Bus (70B, 70C, 7DB, 7DK, 70J,
7. CARAVELLE IV Bus (70B, 70C, 7DB, 7DK, 70J, 70K, 7DC, 7DJ)
8. SHARAN (7M8, 7M9, 7M6)
9. ALHAMBRA (7V8, 7V9)
10. TRANSPORTER IV Van (70A, 70H, 7DA, 7DH)
11. EUROVAN IV Van (70A, 70H, 7DA, 7DH)
12. TRANSPORTER T4 Van (70A, 70H, 7DA, 7DH)
13. TRANSPORTER Mk IV Van (70A, 70H, 7DA, 7DH)
14. TRANSPORTER IV Platform/Chassis (70E, 70L, 70M, 7DE, 7DL, 7D
15. TRANSPORTER T4 Platform/Chassis (70E, 70L, 70M, 7DE, 7DL, 7D
16. TRANSPORTER Mk IV Platform/Chassis (70E, 70L, 70M, 7DE, 7DL,
17. See more in applications

TOPRAN brand Pre-resistor, electro motor radiator fan are used to control the fan speed in an automobile supercharger. The change in resistance affects the amount of current in the motor's electrical circuit, which in turn controls the fan speed in the supercharger. Fan resistors are mechanical components and are therefore subject to wear and tear, which is the cause of most problems in a vehicle's heating system.

One terminal of the blower fan is connected directly to the negative terminal (also called "ground") of the battery, and the second terminal is connected to the positive terminal of the battery through a resistor. The resistor is connected in series with the electric fan. This means that the strength of the current passing through the fan motor, and, accordingly, the speed of the latter is regulated by a resistor. Using the switch, the motorist sets the fan speed he needs, including one or another resistor from the block in the circuit (each of the resistors has its own resistance). There are also two additional options in the control system - one of them turns off the fan altogether, and the second one sets the maximum fan speed. When the fan is turned off, its motor is simply disconnected from the power supply.