[njsteve]

On a whim I went to Autozone and bought a Wells brand #TU5, which is the replacement sender with the slide-on terminal. I tested it against the mechanical gauge and the dash gauge. Here are the results when the car was warmed up and driven four miles. (ohm readings made by touching pos lead to terminal end and neg lead to outer casing of sender unit):

TU5: when the engine was cold and the ambient temp was 80 degrees, the factory dash gauge read 0. At this time the ohm reading was 000.548. Once the car was warmed up and driven 4 miles, and a mechanical gauge capillary unit was immersed in the radiator coolant, the mechanical gauge read 160 degrees. At the same time the dash gauge also read 160 degrees. The ohm reading at that time was 135.500.

When the Lectric Limited model 01513321 was at 80 degrees ambient temp and the engine was cold, the dash gauge also read 0 and the ohm reading was 000.549. When the car was warmed up, driven 4 miles, and the mechanical gauge read 160 degrees, the dash gauge read 215 degrees and the ohm reading was 348.000.

As you can see, the $25 Lectric Limited sender that is sold as "correctly calibrated" was nowhere near as accurate at the $6 Autozone TU5 made by Wells.

I have 70RAIII sending me an original used, GM 1513321 next week so I can get the readings off of that one and compare. (I'll most likely end up using that one in the car, just to be truly correct)