Nissan Repair: Nissan Altima Repair, nissan altima, nissian

Question
1994 Nissian Tachometer not operating normally, pluses rapidly. Would the problem be the tachometer itself or other components? The only identified component is the ECM, not sure what the source is for the pickup?

Answer
August,

It sounds like the tach is going bad as the hall effect pickup is also what drives the computer.  If the hall effect pickup was defective your computer would be throwing a code.  Take the cluster out and check for a good connection at the multi pin connector.  If that fails you should check the tach out for function.  Figure out what the impulse should be and duplicate it with a power supply.