CM850 Electronic Control System – 019-437   Station Select Switch

The Station Select Switch is a monetary switch located on the control panel. The rocker switch is used to change the station selected. The station select circuit consists of the station select signal line, the keyswitch line, and the rocker switch.

If INSITE™ electronic service tool is available, monitor the switch for proper operation. If not, follow the troubleshooting procedures in this section.

Locate and remove the station select switch from the connector.

Adjust the multimeter to measure resistance.

Touch the multimeter probes to the station select signal switch prong
(3) and the keyswitch prong (2).

Turn the switch to the OFF position and measure the resistance. The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, the switch has failed. Replace the switch.

Touch the multimeter probes to the Cruise 1 signal switch prong (3)
and the battery ground prong switch prong (2).

Turn the switch to the Cruise 1 position and measure the resistance. The multimeter must show an closed circuit (10 ohms or less).

If the circuit is not closed, the switch has failed. Replace the switch.

Touch the multimeter probes to the Cruise 2 signal switch prong (1)
and the battery ground prong switch prong (2).

Turn the switch to the Cruise 2 position and measure the resistance. The multimeter must show an closed circuit (10 ohms or less).

If the circuit is not closed, the switch has failed. Replace the switch.

Check for a short circuit from pin to pin.

Touch the multimeter probe to the Cruise 1 switch signal prong (3). touch the other multimeter probe to the Cruise 2 switch signal prong(1).

Turn the cruise control switch to the OFF position.

The multimeter must show an open circuit (100k ohms or more).

If the circuit is not open, there is a short circuit between the Cruise Control 1 and 2 signal lines. Replace the switch.