Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 383 / 881

CHART 3004. TROUBLESHOOTING (PROPELLER DEICER SYSTEM)
Trouble Cause Remedy
Ammeter shows zero current Tripped circuit breaker Locate and correct
all phases of the timer switch. short before setting
cycle. circuit breaker.
No power from airplane. If no voltage into switch,
locate and correct open.
Circuit breaker or switch If no voltage at C/B output
faulty. with voltage at input and
C/B does not reset, replace
C/B. If voltage is OK at output,
check switch in same
manner. If voltage is OK at
switch output, go to next
step.
Ammeter faulty. (If some Test for voltage up to
or all deicers heat with and out of ammeter. If
ammeter at zero, replace low output and input satisfactory,
the ammeter.) replace ammeter.
If no voltage to ammeter,
locate and fix open between
switch and ammeter.
Open ammeter to timer. Disconnect harness at
timer and check Voltage
at Pin B (of harness) to
ground. If none, locate
and correct open.
Ammeter shows normal Open in wiring between Use heat test to find
current part of cycle, timer and brush block deicers not heating and
zero current rest of assembly. test for voltage on that
cycle. contact of wire harness
plug. (At brush block
assembly.) If zero after
1 minute, locate and
fix open in wiring from
timer to wire harness
plug .
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
3 0 - 6 2 - 0 0
Page 30-23
Revised: May 15, 1989
2E3
PIPER AIRCRAFT