I bought a new multimeter today and checked continuity. The base (threads) of the sender are firmly grounded. I checked against the engine block, not just the pan. Zero ohms. The sender is not shorted out. The reading from the output to ground is approximately 1,960 ohms. The specs on this sender are: 1,123 ohms @ 100F and 65 ohms @ 250F. Since this gauge set uses the same sender for water and oil temperatures, I checked the water temp sender, and it also read 1,960 ohms. I don't have the full calibration curve on the sender, but since they're the same part # and have the same reading, I think it's fair to assume that the senders are OK. I also checked the continuity of the wire from the sender to the toggle switch that selects water or oil temp, and from the switch to the gauge. Everything checks out.