My excavator is throwing a code for swash plate sensor. I thought I could test it with an ohm meter buy apparently I'm wrong. How does this thing work? Is there an easy way for me to test them?
I don't think you need to remove that sensor to check. You can test while it's still mounted on the main pumps. Anyway, you can test by supplying 5V DC to A (+) and B (-) then pushing the axis of the sensor. The voltage between B (-) and C (signal) will change linearly according to the travel stroke of the sensor axis.
That makes sense to me, but then I would think I could measure ohm readings between A and C, and watch them change as I stroked the sensor. I was unable to do that, but changing out the sensor fixed the machine. I just like to understand what I'm doing and why.
I really don't know what kind of sensor this is! There are many types of linear positional sensor. If it is a potentiometer then you will likely see the resistance between pin B and pin C change as you push the axis of the sensor. But I am sure that if you measure the voltage, you will see that the voltage between pin C and pin B changes proportionally linearly with the changing stroke of the sensor axis. Attached picture is wiring diagram for voltage test.