Tach Always Indicates Too High Or Too Low, No Tach Indication, Tach Indication Erratic

Ensure engine is operating properly and not misfiring. Disconnect battery ground cable. Remove cluster. Measure resistance between cluster connector "A" terminal No. 20 (Tan/Yellow wire) and ignition coil. See Figure . Wiggle connections and wiring near ignition coil to check for intermittent connection. If resistance is less than 100 ohms, replace cluster. Recheck operation. If resistance is greater than 100 ohms, check wiring in circuit No. 11 (Tan/Yellow wire) for open circuit.