Gas Gauge not fully functioning

Vehicle: '72 E Targa

Background: Replaced original tank with Reproduction (I know dumb move..I was a novice when I did it). Replaced sender unit in tank.

Problem: Gas Gauge reads almost full when tank is topped off. Almost immediately needle goes to 3/4 and then works properly to a little less than 1/2 and then does not work until I sputter to a stop on the side of the road at which time it has read anywhere from a 1/4 to 1/2. The low fuel light never comes on.

Any help / suggestions are appreciated.

Is there a way to bench test the gauge? Or should I just pull it and send it along to North Hollywood?

Is it possible the new sender unit is improperly installed?

Thanks in advance for your help.

Just got the New Esses, Since joining this registry The Esses is now as anticipated as Excellence and Sport car Market. To all of the members who put it together, THANK YOU!

My method is to remove the sender from the tank, plug the electrical connector back on, turn on the ignition, turn sender upside down, you should hear the float hit the top of the sender, now look at your gauge, it should be reading full, now turn the sender right side up, you should hear the float hit the bottom (empty !), now your dash gauge should read empty and the warning light should be on. (if the bulb isn't burned out) If you don't hear the float sliding freely you have a bad sender, if the gauge reads both full and empty limits then it is okay.

This may help as well http://www.pelicanparts.com/techarti...er_replace.htm