I have a 1992 GT. The kid i bought it from put a stall converter in the automatic trans. When the car starts the tach go rite to 3000 rpm even when the car is at idle. When the car is reved about 3000 rpms the tach moves and then drops down to 3000 rpms and stays there. How does the tach work. Is it a cable of some sort connected to the transmission or electronic. I heard some where that if the circuit board on the back side of the gauges has cracks in the circuit the tach will not work properly. They said to take the gauges out and have some place re soder the circuits and that might fix it. How do you take out the gauges...step by step will help a lot. thanks