i have this problem with my tachometer... when my in-laws bought the car, my tachometer sya na nakainstall sa gilid, yung ganagamit sa mga sskyan na pangkarera tapos napansin ko ung original tachometer nya sa dash panel hindi gumagana... ung needle ng original tachometer tumataas baba lang ung reading but it doesn't follow ung tamang reading kapag inaapakan ko yung gas pedal... sometimes it even goes to the maximum level and nagstay lang sya dun... ano po kaya pwede kong gawin dito...