Fuel level sensor

[Blu]

My fuel gauge hasn't worked since I got this. Yesterday I removed the sensor, and it works find and the level reader in the dash works fine. But as soon as I install it in the tank, it reads empty. I took it out time and time again, works fine, but in the tank, not. Checked the float, float floats like it should. Something is obstructing the float in the tank. I swung the unit back and forth from one side to the other and left in in the middle of the swing. I have half a tank, and at least now it reads one notch above empty. I'll take it out today and fill it and see what happens. But is there a trick to this? There doesn't appear to be any indicator as to where it in supposed to be positioned. I'm glad everything works, I just need it to do it's job.