Cessna 172S Annunciator
Low Fuel Annunciator
The Left or Right Low Fuel Annunciator, or both Left and Right Low Fuel Annunciators, will illuminate when the fuel in the associated fuel tank(s) is less than 5 gallons for more than 60 seconds.
Oil Pressure Annunciator
The Oil Pressure Annunciator will illuminate when the oil pressure is less than 20 PSI.
Low Vacuum Annunciator
On airplanes with dual vacuum pumps, the Low Vacuum Annunciator will illuminate when one (or both) of the vacuum pumps are inoperative.
Low Volts Annunciator
The Low Voltage Annunciator will illuminate when the system voltage is less than 24.5 volts.