Altitude Switch

This switch contains a microswitch which performs the "On-Off" operation according to change in atmospheric pressure.
1. Disconnect ground cable from battery.
2. Remove altitude switch from vehicle.
3. With an ohmmeter connected to switch leads, orally blow through discharge port or suck back. Altitude switch is satisfactory if a "click" is heard and continuity exists on ohm meter scale.
4. Altitude switch is pressure-set at factory and no further adjustment is necessary
5. If switch is found inoperative, replace the switch.