Are all temp guages the same

[woodlandfarms]

So I need to add a temp guage to an existing thermostat. Are temp guages pared with thermostats, or is it required that the probes produces the same resistance? I am wondering if I have to change the probe as well?

 

[varmint]

Simple and reliable engine coolant temp. gauges usually come with a liquid probe permanently connected to the gauge. You just have to install the probe in the coolant using an available fitting location- maybe on the thermostat housing? The thermostat, unless I am missing something here, is totally separate from any gauge.

 

[Rocky Hoffler]

You have mechanical and electrical the mechanical ones are one unit. And you have to pair electrical with correct sending unit

 

[woodlandfarms]

Nope you guys have it right. I have a spare electical oil temp sensor on my Deutz Engine (sorry, should not have said thermostat, I made this more confusing), wanted to hook up a second temp guage and also use that same guage to manage my hydraulic temperature. Use a little rocker switch to check back and forth. Probably overkill.

 

[Texasmark]

Electrical gauge deflection is controlled by current. You have the gauge and the sensor in series across 12v and gnd. The gauge and sensor are matched so that the gauge deflection is proportional to the resistance of the sensor, aka temp of whatever you are measuring, makes no distinction there other than the resistance of the sensor and physical characteristics.

So, for you to do what you want to do, you have to have what I said. Either that or make yourself a chart for the one that gives the wrong reading on the gauge. However, you will have to determine what is the correct temp by another sensor of some sort. Nothing wrong with the switching back and forth part of your plan.

Mark