Figure 8-28. Ice Detection System
8-46. CARBURETOR ICE DETECTION SYSTEM TEST.
—CAUTION—
Do not attempt to test the probe or instrument by applying a voltage to
each. Any voltage over 2 volts will burn out the probe lamp, sensor,
and the instrument red light switching transistor.
a. To test the probe:
1. Disconnect probe from instrument at the knife connections.
2. Connect a red + ohmmeter test probe to black wire of ice detection probe.
3. In a subdued light (not in sunlight) touch the black ohmmeter test probe to the red wire of the ice
detection probe. The ohmmeter reading should be approximately 600 ohms with ordinary light on the probe
sensor.
4. Cover the ice detection probe sensor with the hand to eliminate most light. The ohmmeter reading
should be very high: approximately 10,000 ohms or more.
5. Remove ohmmeter black test probe from the red wire and touch it to the white wire. The ohmmeter
reading should be approximately 5 ohms. This indicates that the probe lamp is operating.
6. Test probe housing for short to ground. Housing is insulated.
7. If the tests contained in the previous steps are satisfactory, the probe will operate satisfactorily.
B940
ARP
107 AP
CARBURETOR
PROBE
KNIFE CONNECTORS
BLACK
WHITE
RED
RED
R
E
D
W
H
I
T
E
B
L
A
C
K
B
L
A
C
K
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
POWER PLANT
1K13