N2: Check Wire Between Instrument Cluster & Speed Control Amplifier

With the ignition key in the OFF position, remove the instrument cluster. Locate and disconnect the speed control amplifier connector. Locate and disconnect the instrument cluster connector C2. Measure the resistance of the Red/Yellow wire between the instrument cluster connector C2 and the speed control amplifier connector. See WIRING DIAGRAMS  . Measure the resistance of the Red/Yellow wire between the instrument cluster connector C2 and ground. Is the resistance less than 5 ohms between the instrument cluster and the speed control amplifier and greater than 10,000 ohms between the instrument cluster and ground? If yes, replace the instrument cluster. If no, service the Red/Yellow wire.