Tachometer not working (?)

I have a 78 280z and since I have started restoring it (in the process), rebuilt engine and all .... my tachometer has not worked. Actually I do not remember if it was working when I had parked it 10 years ago. Before I look for a new tach ... where does it connect too in the engine side? So that I can check all connectors to make sure they are not corroded. I did pull it out from the front dash to make sure all connections were good. The needle itself did not move as freely as the speedometer. Is it supposed to? Any help or suggestions will be appreciated.:stupid: