My rev counter does not work on my kawasaki er5 1999

The ER5 has got an electronic rev-counter, no cable.

Like the oval rear brake-drums this is another ER5 bugbear, the rec/rec fails, the battery boils and the rev-counter is usually a victim too.
Often on ER5 specific forums there will be someone who repairs the circuit board and sells the repaired units much cheaper than a new one. it's usually a tiny zener-diode that is killed.

Cable seems fine ?Unscrew caps from tach and engine. Remove cable from housing by pulling it out either from tach side or more likely, engine side.. if it comes out in 2 pieces it's' broken.and you need to replace.