Temperature switch on jetta 2 - 2001 Volkswagen Jetta TDI

There are 2 of them. One is marked HVAC, one is marked blower. Owners manual or panel lid say which one. If the blower works go the HVAC. If you can control the vents, they switch air flow. Then you could be low on freon, or have a bad blend/temperature door motor.

Hi. It should be on the gearbox side of the engine.:you will see black plastic housing and the grey temperature sensor will have a 2:pin plug

No, it uses the engine temperature sensor and rad fan module.

Your Jetta 2 modulator is not compatible with the Jetta 3 electronics, especially when it comes to the coil as they give different stokes of spark to the distributor. Oil switch must have a pressure leak. Replace the switch as a small leak of pressure can cause the sensor buzzer to sound. The modulator have no influence on the oil pressure switch.

1) Is there enough coolant in the radiator?
2) Have you noticed if the electric fans are kicking on when the temp is going high? I'm guessing that they are not, the temp switch may be faulty.

You are talking about the thermo electric cooling fan, its operation is independent of the car's electical system. It is switched on and off by the engine temperature. When you park, the engine heat soaks upward to heat the thermostat turning the fan on. It will run until the engine cools down and the thermostat switches it off. Quite normal operation.

Hi,

Fan Relay switch is stuck open. This of course assumes your temperature sensor is working appropriately. Which I assumed since you seem to know that the engine is running hot.

Replace the fan relay switch. The relay switch is tripped when the temperature sensor tells the computer the engine is too hot.

Until you get the relay switch replaced, you can either by-pass the relay switch and directly connect the fans to the battery, or turn on your A/C ALL the time and use it at a minimum setting. This will keep the cooling fans running at all times.

Hope i helped you.

Thanks for using ' Fixya ' and have a nice day!!

disconnect the cooling fan temperature sensor on the engione that turns on the fan, if the fans runs the switch/sensor is defective.

Check for a switch at lower part of rad. Should see a wire harness & plug on a sensor at bottom of rad. This sensor/switch also operates fan on/off according to coolant temperature. You may need to disconnect battery to get at it safely.

A thermal switch controls the radiator fan and if the temperature of your radiator is above a preset temperature value, the thermal switch will close and the fan will turn on and will stay on even after you turn the motor off, until your radiator temperature cools down. I wouldn't worry about.