hi i have a 63 gmc with dolphine gauges(mechanical),i seem to have a problem with the fuel gauge.when i fill the tank up it only reads 1/4 a tank so i changed out the sending unit,and it still reads 1/4 a tank.does anybody have any advise.please respond.
It is possible that you bought the wrong feul guage. The guage uses ohms to read fuel level. If you have the wrong range of ohms it can make the guage always read emty. Check your part number on the guage and see if it is right. You have two choices on guages.
If you replaced the sender with a 1963, it's the wrong ohm. The 63 uses a 30 ohm sender and the newer guages use a 90 ohm unit. So when you are full it reads a third of the value of what the guage is expecting. Use the sending unit that came with the dolphin guages. The problem is that a new fuel pickup will need to be added to the tank. As you know, the factory sender shares the fuel pickup function too. It might be a good time to move the fuel tank under the bed !! Val
Same problem I have with my '77 K5. LMC truck only offers one ( one size fits all fuel gauge) for my model truck. When the tank is empty it reads 1/2 tank.
