Duster temp gauge problems

The sensors are just thermistors, and they work across a very specific resistance-temperature range. Are you comfortable working with VOM's? If so, find yourself a 100 ohm (or higher) ohm pot (potentiometer), wire it such that it "replaces" the sensor (note quotes: the wire from your dash going "into" the pot, and the wire coming "out" of the pot should be on a good ground), and while turning the pot, have someone watch the gauge, as it should move smoothly across it's full sweep.

If it does, the gauge is ok.

Then, adjust the pot such that the gauge is near the middle of the range.

Remove the pot, check that resistance, and write that down.

Then check that your resistance across your sensor is compatible, or somewhat consistent, with the value your wrote down....which should also be somewhat consistent with the values in response #6. IOW, heat the sensor up to, oh, I don't know...175 degrees or so and then quickly measure it's resistance. (Or maybe do this first....)

My guess is the sensors you're buying are of the wrong resistance scale (incompatible with your gauge).

And as long as you have a good pot, you could always check the gauge "H" and "L" values as well, and then compare them to the sensors.