Piper Navajo Chieftain PA-31-350 Service Manual page 858

NAVAJO CHIEFTAIN SERVICE MANUAL
TABLE XIV-V. TROUBLESHOOTING CHART
(PROPELLER DEICER SYSTEM) (cont.)
Trouble
Cause
Remedy
Ammeter shows nor-
mal current part of
cycle, low current
rest of cycle.
(cont.)
Ammeter shows low
current over entire
cycle.
High resistance in
circuit with low
current.
Aircraft voltage
low.
If not in contact of brush
to slip ring (including
ground brush), trace
wiring to deicer and to
timer to fix partially
broken wire, loose or
corroded connection.
Check voltage into switch.
Ammeter faulty.
High resistance up
to timer.
Test for voltage up to and
out of ammeter. If low or
zero output and input
satisfactory, replace
ammeter. If no voltage to
ammeter, locate and fix
open between switch and
ammeter.
Check for partially broken
wire, loose or corroded
connection in wiring from
aircraft supply to timer
input.
Ammeter shows excess
current over entire
cycle.
Ammeter faulty.
Test for voltage up to and
out of ammeter. If low or
zero output and input
satisfactory, replace
ammeter. If no voltage to
ammeter, locate and fix
open between switch and
ammeter.
Reissued: 9/23/80
ACCESSORIES AND UTILITIES
4F14