Rpm GUAGE not working, clock works sometimes, if you tap on clock face

[smokinrt]

rpm guage never works, can you tell me how to test, which side of coil do I connect to.  Does it also tie into ignition?
Also, has anyone fixed a clock that operates sometimes.  This is a charger RT 69', Tic Toc Tach, original.  Thanks a bunch for any help.

smokinRT
Bryan
bryanjs@sbcglobal.net

[Just 6T9 CHGR]

the tach is connected to the (-) side of the coil and the radio fuse for power....it is grounded to the cluster housing.
The clock is probably on its way out.
Quartz conversion kits as well as new PC boards for the tach are available from www.rt-eng.com