Ammeter Shows Normal Current Part Of Cycle, Low Current Rest Of Cycle; Ammeter Shows Low Current Over Entire Cycle - Piper PA-44-180 SEMINOLE Maintenance Manual

CHART 3004. TROUBLESHOOTING (PROPELLER DEICER SYSTEM) (cont)
Trouble
Ammeter shows normal
current part of cycle,
zero current rest of
cycle. (cont.)
Ammeter shows normal
current part of cycle,
low current rest of
cycle.
Ammeter shows low current
over entire cycle.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
Cause
Open between brush
block assembly and
deicer lead straps.
No ground circuit, one
engine.
Open or high resistance in
deicer or slip ring leads.
High resistance in circuit
with low current.
Aircraft voltage low.
2E4
Remedy
If there is voltage to brush
block wire harness plug,
try voltage at junction to
deicer lead and slip ring
Lead. If no voltage. find and
correct open in wiring
within brush block or no
contact of brush to slip
ring.
If voltage is found at
deicer leads, locate and
fix open from deicer to
ground.
Disconnect deicer leads
to check resistance. If not
OK, replace faulty deicer.
If satisfactory, locate and
fix open in slip ring leads.
Check deicer wire harness
leads for continuity. Ohmmeter
needle must not
flicker when leads are
stretched or flexed. Replace
as required.
Check for contact of brush
to slip ring. Check wiring
from timer to deicers for
loose or corroded connections
and partially broken
wiring. Correct as required.
Check voltage into switch.
Revised: May 15, 1989
3 0 - 6 2 - 0 0
Page 30-24