the temp gauge sending unit has two pins on it.
one pin is for the gauge and one for the light.
at 100F there should be 1400 ohms between the pin and the base of the sensor.
at 260F there should be 55 ohms.
i am not sure at what temp the pin for the light should close and have 0 ohms between it and the base, but I would expect it to be an open circuit at least up to 220F
i have to leave the house to put a roof shell on Ling.
if you still need more help when i get back i'll put up some pics.
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Buddy - there are two "G"s in my name
Ling = 84SE-350-N2O-Poly-Mr.Mike seats-Sequential turn signals-short shifter
Julia C = 85GT stock (kinda)
KCFOG