I have a 1995 Mustang Gt and the tachometer is jumping around, sitting idle or hitting the gas, it will jump all over the place. Last week when I shifted gears it didnt fall back down to the appropriate rpm but instead made an entire circle around the gauge and was stuck there until I turned the car off and then back on. Theres no issue with the transmission, just the gauge, and only the tachometer. Any help is appreciated.

 

Get an aftermarket tach.