Help... OK, what do you do when the new replacement gas tank sender unit doesn't work after less than 4 months. This is on a 69 Mach 1. All I get now is a dash meter reading floating loosely in the middle of the gauge. Could my dash gauge have possibly gone bad, or should I pull the tank gauge? What's the acid test to determine which component is bad? It's frustrating that aftermarket parts are made so poorly. Do I need to find a NOS sender, or is there some manufacturer out there now that creates a quality part? This isn't a fun job to repeat again.