Gas gauge problems

Hey guys,I am having some problems with my fuel gauge on my 71 scamp.Here is the problem...I have replaced the pc board on the cluster along with the voltage limiter,the temp gauge works fine but I can't get the fuel gauge to work.I have a dim bulb reading on my circuit tester but it doesn't pulsate,the temp doesn't either but it's working good.If I ground the sender wire to chassis the gauge reads full,but if I ground the sender to body no reading on gauge.The sender is fairly new from classic ind,but I haven't done a ohms test on it yet.Have I missed something?Thanks