Nissan Repair: 1996 infiniti g20 erratic rpm meter, 1996 infiniti g20, phillips screwdriver

Question
Very challenging question: My RPM meter has been erratic for months and then when my first 3 speeds(4th speed works)on my blower motor stopped working , the erratic nature of my RPM meter stabilized.  I know the meter was bad and I do not actually have a problem with my RPM.  What is the fix for this?  Hopefully it will be quite similar to Nissan.

Answer
Cindy,

The Tach, if it operates erratic, is probably the tach itself that needs to be replaced or the resistor in the circuit is going out.  The nice thing about a 1996 car is that you can hook up a scan tool and get the tach feed to display.  The signal is provided from the cluster, where it plugs in, to the computer, so if it reads correctly on the scan tool then you know it is the tach.  You coul go to Autozone or Checker and get them to hook up their scanner, tell them the problem and you want to see if they can read the engines RPMs with their scan tool.  If they car then I would replace the tach.  If not, then it is probably the resistor or wiring.  But, if the latter was the case the computer would be throwing a code.  The blower speed thing is just a matter of changing the blower resistor unit.  It is located under the dash on the passenger side and in the blower case.  Remove the glovebox and you will have access.  Purchase the new part and you will be able to recognize it.  All it takes is a phillips screwdriver to do the change.