testing a temperature guage

[IH_4_Me]

Hi there,
Just wondering if anyone knows how I could test a temperature guage to see if it is operational. My tractor is in a million bits at the moment and the gauge was disconnected long before I pulled the tractor apart so I dont know if the gauge works or not.

Thanks,
Glenn

 

[RoyJackson]

You've have to rig it to a 12 volt auto battery (or 6 volt, if that's your system's voltage).
Then put the sender in a pan of water. Heat the water to boiling (212° at sea level).

That should put you in the ball park.

 

[slowrev]

If your temp gauge is the capillary tube type ( no electricity required ) Do not crimp the tube or it will could be ruined. Use the boiling water method to check.

 

[RickB]

If you are using Roy's method on a single wire electrical sender, run a ground from the sender's body to the voltage supply's ground.

 

[Junkman]

If the gauge is the older capillary tube type, putting it in a pot of hot water will tell you if it is working, but will not tell you the accuracy unless you also check the temperature of the water with a known correct thermometer.
If the gauge is a electrical gauge with a sensor that screws into the water jacket of the engine, you will need to know what the circuitry of the system is. Some use a sensor that is opened to ground to turn on a signal light commonly known as a "idiot" light. Others operate a gauge that is marked from "cold" to "hot" or in vague indication of degrees. Some of these are mounted in dash pods that have built in voltage regulators that "feed" a specific amount of voltage to the gauge. If you put the wrong amount of current to the gauge or the sender, you could damage the unit and render it useless. Considering that the rest of the tractor is in "parts", I would work on getting everything back together and leave this for last and do a "live" test when the engine is together. This would be the safest way if it an electrical unit in my opinion.