Why does my fan kick on and off?

If your blower is constantly turning on/off when the furnace isn’t heating… …you most likely have a bad fan limit switch. The system uses a “temperature probe” to detect temperature changes inside the heat exchanger (see image below) and turns your blower on and off in response.

Why Does My car fan come on straight away?

If the fan comes on, you may have a bad temperature sensor or gauge. 2. A cooling fan temperature switch (or sensor, in some vehicles) can also get stuck, which may cause the fan to run continuously any time you turn the ignition key on or start the engine. Troubleshoot the switch.

Is it normal for radiator fan to turn on and off?

Your car fan will run for a few minutes after you turn off the car then turn it off. This is normal in many vehicles, such as BMW or Mercedes-Benz. The radiator fan may run up to five minutes and sometimes longer. Unless there is an electrical issue, it may stay on all the time until it drains the battery.

Why does my cooling fan keep coming on?

Cooling fans stay on at all times If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times.

What can cause a / C blower motor to turn off?

My best guess would be that the blower motor may have bad bearings or other issues causing it to draw too much current, causing the overcurrent protection on the motor to kick in and shut the motor off.

What happens when a blower motor relay wears out?

Without it, the AC system will not be able to circulate any heated or cooled air. The blower motor relay controls the current used to power the blower motor, and is subject to the constant on and off switching. Over time, it can eventually wear out.

Why does my furnace blower keep turning off?

I just ran across an intermittent blower issue (cycling on and off constantly during call for heat from the thermostat) that was due to a poor ground connection on my 120 volt to 24 volt transformer on an old Janitrol furnace. The ground side of the 24 volt half of the transformer had 2 wires connected to it.

Why does my car fan only work on high speed?

If the fan is working only on high speed, it is probably a shorted blower motor resistor. The resistor is responsible for changing the voltage to the blower motor. If it is shorted, the voltage passes straight to the blower motor causing only high speed.