So my fuel gauge reads just under half, doesn't move and hasn't since I bought the car 2 months ago. I know this because it ran dry while working on getting things done for the safety inspection. I tested the connector to tank and the resistance is 34.6 ohms which would read half and sounds right since I've put some fuel in to get it around. Testing the connector fwd unplugged gauge moves to full and grounded purple it settles back to just under half. Any thoughts ? TIA

 

My fuel gauge did something similar at one point and it ended up being my flex hose from the pump to the sending unit. The hose has a loop in it and the loop got in the way of the fuel level float so it would never read below a certain point, since the float arm was getting caught on that loop. I just rotated the loop out of the way and it's all good.

 

Yeah it most likely is mechanical.

 

Should the gauge not zero when grounding the purple wire with ignition on?

 

The gauge should read empty. You should investigate the sender and wires