Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions

Wiring Diagram for the Radiator Fan

Model: (Various brands) Various
Part: Checks and maintenance

Here we see a wiring diagram for the radiator fan, which varies slightly depending on the car model, but the basic principle is similar for most vehicles. The fan receives power from the battery through a dedicated fuse, and the circuit is controlled by one or two relays (for low/high speed). The low speed is activated by the temperature sensor when the coolant reaches a certain threshold: the relay closes the circuit with a resistor in series to reduce the speed. The high speed is activated at higher temperatures (above 100°C) or when the air conditioning is on. The relay bypasses the resistor, powering the fan at full capacity. The fan is connected to ground to complete the circuit.

Posted on 2 April 2026 by ScegliAuto

Video tutorial

Related tutorials

How to test the radiator fan
How to test the radiator fan
(Various brands) Various If we have doubts about the radiator fan of our car being defective, we can follow this video, which will guide us through a simple system to test it…
What is the Purpose of the Cooling Fan?
What is the Purpose of the Cooling Fan?
(Various brands) Various The engine cooling fan is located at the front of the vehicle and pulls (or pushes) air towards the engine; when the engine reaches about 90/92°C, th…
How to Replace the Radiator
How to Replace the Radiator
(Various brands) Various Release and lift the bonnet. To access the radiator, you will need to remove the mechanical parts behind it that obstruct access. You will find a gui…

Other guides you may be interested in

    Frequently Asked Questions

    • Vari - What does it mean when the message "insp" appears on a car? Read answer
    • Vari - What problems does the Kymco Downtown 300i have? Read answer

How to Open a Stuck Boot on the Peugeot 407?

On the Peugeot 407, the boot may become stuck, possibly due to a problem with the control button or the lock actuator. In such cases, you can perform an emergency opening by following the simple procedure shown in this tutorial. First, open the rear doors, then lower the seat back by operating the release lever. Next, go inside the boot, locate the lock, and manually operate it using a flathead screwdriver. The boot will then be free to open.

Watch the video!


by ScegliAuto

More videos