Testing Temp Sensor?

[Eric_Whitney]

Could anyone tell me how to test a temperature sensor? I have a Ford 1210 that has Oil, Temp, and Battery lights. When I turn the key right before starting the Oil and Battery light stay illuminated until the motor starts. The Temp light never comes on, but I don’t know if it really should? I checked the Temp Bulb and it and the socket are good. Any idea how to test the sensor, I want to make sure I know if the tractor is overheating. Thanks

Eric

 

[uhmgawa]

</font><font color="blue" class="small">( Could anyone tell me how to test a temperature sensor?)</font>

It depends whether it is a switch or resistive, but the
process is the same assuming you can remove the sensor.

Place an ohm meter across the sensor and put it in a
container of cold water along with a known accurate
thermometer. Heat the water gradually and note the
resistance vs. water temperature or where the switch
actuates. You can compare this to the manufacturer
specification for the sensor.

 

[dltimmons]

Eric,

To test the light and the wiring from the sensor to the light, remove the lead that is connected to the sensor. With the tractor running, ground this lead, either by directly touching it to a good ground, or by attaching a jumper to ground. If the light comes on, then you know that the circuit from the sensor to the light is good. If it does not come on, its time to start tracing the wire to find a bad connection, or break in the wire some where.
This also works for guages to tell whether the guage, wiring, or the sensor is bad.
Good luck,

DT

 

[RickB]

There is no test mode at startup on your temp gauge.

 

[Eric_Whitney]

Thanks Rick,

That makes me feel better knowing it should not light at start up.

 

[htiek126]

I have never been able to find manufacturer's specs for temperature sensors. Do you have a good source?

 

[uhmgawa]

</font><font color="blue" class="small">( I have never been able to find manufacturer's specs for temperature sensors. Do you have a good source? )</font>

This can be found in the service manual.