Fuel Low-Level Light Diagnostic
100191-00
Perform this diagnostic procedure if the fuel low-level LED in the fuel gauge fails to illuminate when fuel level is less than 2 gallons.
Applicable Aircraft Serial Numbers
All
Type of Maintenance
Line
Level of Certification
LSA-RM
Task Specific Training Required
No
Special Tools Required
No
Parts Required
None
Aircraft System and Number
07—Fuel System
Safety Equipment
As Needed
Consumables
None
Task Instructions
1. While looking at fuel gauge, turn master switch on, pause for a moment, then off. The red LED in the fuel level gauge should illuminate momentarily after the switch is turned off. Several cycles may be needed to be sure of the result. If the LED is not seen, the gauge could be faulty or the low-level switch may have become disconnected or damaged.
2. Verify that the surface of the fuel in the tank is below the low-level sensor (<2 gallons).
3. Check that signal power is getting to gauge:
a. Unplug the connector at the fuel gauge.
b. Turn master switch on. The voltage between Pin 1 and Pin 3 at the aircraft harness gauge connector should be 12v. If it is not, the sensor may be faulty.
c. Turn master switch off.
4. Check condition of aircraft harness:
c. Unplug low-level switch from aircraft harness.
d. Check for continuity between the following pins in the aircraft harness connectors. If there is no continuity, then the aircraft harness may be faulty.Gauge Pin 1 and Sensor Pin 1Gauge Pin 2 and Sensor Pin 9Gauge Pin 3 and Sensor Pin 3
5. Reconnect gauge and low-level switch connectors.
6. Reinstall right seat back closeout and right baggage floor.
Verification Method
While looking at fuel gauge, turn master switch on, then off.The red LED in the fuel level gauge should flash momentarily after the switch is turned off. Several cycles may be needed to be sure of the results.
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