i installed a combo gauge with the oil temp gauge and it doesn't register oil temp. when i turn on the ignition, the needle on the gauge moves to bottom of range so i'm getting power to the gauge. i traced continuity from the transducer to the gauge (but will check again). i'm thinking either the transducer doesn't work (which i doubt and want to know if anyone experienced a failure) or the plate that mounts the sender isn't grounded, like, the paper gasket i cut for between the mounting plate and the cover plate doesn't allow a ground connection.

The "Temp Sensor" screws into the plate and yes there must be a grounding path between the body of the sensor and the battery...

The wire, plugs into the spade connector on the sensor...

The gauge measure the resistance between the two as produced by the internals of the sensor...

2-OH!