Don't know your machine, but auto sensors put out a resistance curve that can be checked in a pan of water by heating and plotting with your VOM. Grounds are important. There are many sensors out their but they will not necessarily work with your guage. If lost look at the sensor thread and then your auto parts store for a new sensor and guage. I have found JC Whitney is a good source, but the thread thing can bite you. Assuming 12 V.