Fuel tank level indicator

[steplift20]

franc couldnt get on the site but i just replaced my gauge and really didnt know how to hook up the wires so i asked the mechanic on my job and he told me how it works and said that no power should ever go to the sending unit only the grounds do its like when you get a headlight that is loe its the groud wire causing it so i had a west marine catolog and it has a diagram of the sending unit and it shows that you have a groud going to the unit and a secound ground coming off the unit to the gauge so there
check it out