autometer fuel gauge

[1979elcamino]

so i've installed all new gauges and all of them work except the fuel gauge. what's happening is it won't read past half it it reads backwards... i've got a good knowledge of 12vdc systems and i've installed a brand new painless harness so all the wires are marked. i've got the gauge properly grouded to a chassis ground, the fuel tank is full and before i call autometer i figured maybe i can look for some help here.

 

[adumb]

did you install a new sending unit?

if the ohm range on the gauge is different from the ohm range on the sending unit it will not read correct.
i know that sunpro fuel gauges operate on a 240 ohm - 29 ohm range. the stock sending unit operates from 0 - 90 ohms.

see what the ohm range is on the fuel gauge. you may need to match it with a new sending unit.

 

[1979elcamino]

good call, thank you!