ELECTROREFIT

For fans with an electronic control unit (ECU) forget such concepts as: first, second and third speed, even in spite of what is indicated in the diagnostic programs. In fans with an ECU there can be more than 100 speeds, since the speed is set proportionally to the pulse PWM signal on the control wire, which can have multiple meanings. By smoothly changing the PWM control signal, you can also smoothly change the fan speed, just as the volume control smoothly changes the volume of the sound. You do not say that you have 2 or 3 volumes in the radio. Such concept as the first, second, third speed can only be used for fans without an ECU, in which the speed is limited by powerful limiting resistors connected to the electric motor using a relay. Or multi-brush motors can be used instead of resistors, in which relays are also responsible for switching various brushes. Let's say we have a fan without an ECU with one resistor and two relays. We can say about this fan that it has two speeds,..