Nissan Repair: tacometer, nissan sentra, sentra

Question
I have a 2002 nissan sentra and I my tacometer is bouncing up and down when I drive with no rhyme or reason, I had a motorcycle once and that is what happened when the tacometer cable got loose, but I can't seem to find the wire, can you help

Answer
iv,

The tach on your car is electric and the wire goes to the ignition coil.  I would check the connection under the hood first.  Second, I would think the connection at the cluster is going to need to be cleaned.  If these two do not resolve the problem then you need a new tach.