Help with repo temp.gauge

Birddog1970, it is the most difficult to figure out I have tried everything I can think of if you figure it out I sure would like to here from you thanks, Marty

Steve, first the repo gauges did not come with any instructions,or sending unit, I never had a large fuel gauge, because I have a clock, my car came with gauges the temp gauge did not work right was always higher the the actual engine temp. I verifed the engine temp with a mechanical gauge which showed when the 180 thermostat opened etc. ran about 190 when it was all warmmed up so I thought I just get the repo gauge and quit playing around well that showed it running too hot again,I changed the sending unit now it was running too cool still not right, I bought a "corrected" GM sending unit guaranteed to be acurate runs too hot no matter what I have done it does not show the correct engine temp. really frurustrating, Marty

71 ChevelleConvert, the repo gauges do not require the little resistor on the back, that was the first problem the repo gauge has the resistance built in you can measure the ohms it should read about 100 ohms if you add the external resistor on the back you increase the resistance and the gauge will read colder than it really is and with out it, it will read hotter than it is? it has been driving me crazy thanks, Marty