I picked up a MOPAR NOS temperature sender for my 300K today. In a bag with a factory part label on it.
I rigged up my fluke tester as well as my calibrated kitchen thermometers and tested it. This is what I recorded:
At 64 degrees Fahrenheit, tap water temperature, I recorded 300 Ohms.
At 180 degrees Fahrenheit in a pot I recorded 36 Ohms.
It wanted to float a little on each end as the fluke is VERY sensitive. I would say no more then one or two ohms if that.
It will be a bit before I can place it in the car as the A/C compressor must come up to get it in. That a PITA this is to change, and one then has to dig out the tools to reset the belt tension and torque all the bolts including the power steering pump as that lower bolt has to come out as well to get the A/C up in the air.
Once done, I will see where the gauge on the dash falls when cold and at running temp.
James