Why is my fan running all the time without heat?
When your thermostat is set to AUTO, your furnace fan should blow only when your furnace is in the middle of a heating cycle. But if your fan runs constantly, regardless of whether your furnace is heating, that’s not normal. There’s a shorted thermostat wire. There’s a shorted wire at the fan limit switch.
Why does the radiator fan not run at highway speeds?
At highway speeds, when there’s sufficient airflow over the condenser and radiator, the switch stays open and the fan doesn’t run. When the vehicle slows or stops, the a/c pressure rises and the fan runs, regardless of engine temperature. In this arrangement the diode is not needed.
When does the cooling fan come on or off?
I’ve read that the cooling fan will run the whole time when either the A/C is on or the vent control is set to defrost, regardless of whether the engine is cold or hot. In my case, the cooling fan comes on when the engine is cold, even with the HVAC off and it will remain running at full speed when the engine is running, again with the HVAC off.
Is there a delay in starting the fan?
This delay is dependent upon engine speed, starting fan speed and clutch temperature. With the engine at operating temperature and at 2,500 RPM, the delay should be less than 30 seconds. varies depending on operating conditions such as temperature, engine speed and starting fan speed. conditions.
What causes a car cooling fan to run continuously?
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. 3.
I’ve read that the cooling fan will run the whole time when either the A/C is on or the vent control is set to defrost, regardless of whether the engine is cold or hot. In my case, the cooling fan comes on when the engine is cold, even with the HVAC off and it will remain running at full speed when the engine is running, again with the HVAC off.
At highway speeds, when there’s sufficient airflow over the condenser and radiator, the switch stays open and the fan doesn’t run. When the vehicle slows or stops, the a/c pressure rises and the fan runs, regardless of engine temperature. In this arrangement the diode is not needed.
This delay is dependent upon engine speed, starting fan speed and clutch temperature. With the engine at operating temperature and at 2,500 RPM, the delay should be less than 30 seconds. varies depending on operating conditions such as temperature, engine speed and starting fan speed. conditions.
What to do if your cooling fan won’t stop running?
The fan will discharge the battery quickly if left running. Open the hood and locate the fuse relay box on the driver’s fenderwell. Remove the lid. Look on the inside of the lid and for the mapping of the fuses and relays with their location. Pull the cooling fan relay out of the box. Replace the cooling fan relay with a new one.