55.2-59 59 Coolant Temp sensor Ohm (resistance) values

[BlouDon]

Nowhere on this forum could I find what the resistance values for the temperature sensor on my 59 235 should be. The only identity marking on the sensor says "12 Volt". I suppose it comes from the days when 6V vehicles were still abundant and you had to be sure to fit a sensor as for 12V vehicle.

So I measured mine:

20ºC -70ºF = 770 Ohm
30ºC - 86ºF = 550 Ohm
40ºC - 104ºF = 350 Ohm
50ºC - 122ºF = 276 Ohm
60ºC - 140ºF = 230 Ohm
70ºC - 158ºF = 182 Ohm
80ºC - 176ºF = 130 Ohm

The temp gauge on my '59 3100 was lying so low (as viewed from the driver position) when the engine is on operating temp (74ºC / 168ºF thermostat), that it was hard to tell if the gauge was operational or not, and I wanted to "fix" this. So I did....

I installed a 390 Ohm resistor in parallel with the sensor (one leg to ground, the other to the sensor connector) and now the gauge sits at around 1/3rd of the scale. This will result in the gauge becoming less responsive (not much though) the colder the engine is (when it does not matter), and more responsive (not much either) the hotter it gets (when it does matter).