i put in a new tank sending unit and fuel lines everything works but the gauge reads full when i turn the key on i ran a ground wire from one of the screws that hold the sending unit in to the frame any help would be great thanks vinny and i tried to do a search but didnt find to much
What gauge? What sending unit? What voltage? Is it electronic or mechanical? How is it wired? You gotta give specific info to get a specific answer.
Mine read full for 7 years until changed the gas cap. Now it works fine. Yes I drove it all the time.
mine did same - 50 chevy, changed sending unit, top of old one had a short from sending unit wire to sending unit housing. Unit may have been good but after all the work of getting the tank drained and out was smart to put in new anyways.
Different tests for different style/types/voltage, for guages and senders, standard old Stuart Warner is disconnect the sending wire from ga and then ground ga terminal, if it goes to full ga is good, sender is shot, Chevy on the other hand won't test like that, there is a total different way to test sender and ga. As Badshifter said need to know more.
sorry about the info its a 54 chevy 6 volt system chevs of the 40s replacement tank and sending unit that was the same as the old one one wire runs from the gauge to the sending unit and i added a gound from sending unit mount scew to the frame
Take the sender wire off at the tank (the one coming from the guage) and touch it to a good ground with ignition key on. The guage should read empty. Then, remove it from the ground and let it dangle in the breeze - guage should swing to full. If the guage works as described above, the guage and all wiring back to the tank is good and the problem is either a bad sender or a bad tank ground. If the guage doesn't work as it should, check the sender wire all the way back to the guage and make sure the guage case is grounded to the dash (you may have to sand some paint here and there to make it work)