Checking Regulator Circuit - Piper PA-24 Comanche Service Manual

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PIPER COMANCHE SERVICE MANUAL
9-58. R-.ulat.'. (D.lco.RaIllY)
9-59. Oaclcin, R.,ula,., Circuit. Altemator failures may t. caused by circuit lIlisconftections,
such u reversed lucl.. or shorted or IfQUDdiJll of terminal. with a saewdriv.r. etc. The follo.inC
provide. a means of loeatinc circuit milCOftlleetioaL It also covers the different types of reculator
panel board circuit trace defects which iDdicate a certain type of wirinl hamell misconnections.
A bumed circuit trace on the reculator pMel board
i l
proof
that
I
circuit misconnection exists, or
occurred at some time. However. a miaconaection will not &1w. cluse a bumecl. circuit trace
even thoulh circuit compoaent failures have been clused.
Before inltaUiDC a new replltor. it is very iml)OrtaDt to mue
SUN
that no wirial circuit
defectl or wirinl hamels lIIilConnections exist. If the wiri.aC h........
is
defective. or if milcon-
nections axist. the new rel'llator will fail too. Futhemore. rapeatH replacement of tIculators
will
only result in repeated reculator failures. ed tbi. will continue Wlti! the circuit defect is
. corrected.
To check the wirinc harness for defect. or misconnectiOllI befora iutaUinl the new recu·
later, oblerve the (o11owinc proeedure.
NOTI
Meter connections are mKe to the ham••• cOlUloctor that hu been
unplulled from th. raeuJ.ator.
a. Check the altem.tor field reli.taaca with an ohmmeter a••howa
in
Stap 1. Fipre 9-24 and
note the rndinc. ~ake sure the muter switch is OFF. Readiap of
1 ...
the
2
ohms. or lIlore
than 8 ohllls indicate a defective field windinl in the altemator or a defective wirinc hamess. If
the readinl is
Within
the 2 to 8 ohm rUle, check th. ralldinl a.ainat the aUow.ble ~Iistane. in
the circuit which can be calculated by dividinC the lpecilied voltaCe for the altemator by the
TYPICAL
BATT!RY
HARNESS
CONNECTOR
JUMPER
LEAD
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FIGURE 9·24. VOLT· OHMMET!R TEST
FIGURE
'.25.
JUMPER CONN!CTION
ELECTRICAL SYSTEM
'SSUED:
8118n2
3
817