12v to 6 v temp sending unit
OK Doc. i think I got it.
When the sending unit lead is grounded ( 0 resistance) it pegs the needle. Takes 30 ohms to get it to read about 220 degrees - as high as it goes.
More resistance, lower temp. 47 ohms - 170 degrees / 68 ohms - 130 degrees and at 100 ohms about 100 degrees, as low as it goes. I noticed it is not a smooth curve. 15 ohms on one end of the scale is about 50 degrees, but 30 ohms difference on the other end is only about 30 degrees. is that normal? big question is - do I ask for a 100 to 30 sender (cold to hot) or the opposite? Turns out the local hot rod shop has many senders, by value, so I'm headed there tomorrow. Thanks, don