Piper SARATOGA PA-32-301 Maintenance Manual page 190

PIPER AIRCRAFT
PA-32-301/301T
MAINTENANCE MANUAL
PRECAUTIONS.
As a preface to testing the charging system, it cannot be over-emphasized how important it is to observe
the precautions listed. Considerable time and expense can be saved by following these simple rules.
1. Always disconnect the battery ground cable before disconnecting wiring or components of system.
2. Avoid contacting alternator output terminal (BAT) as it is directly connected to the battery bus
voltage anytime battery cables are connected and "BAT" portion of master switch is ON.
3. Never connect the battery ground cable until all system wiring connections and components are
complete.
4. When adjusting belt tension, always apply force near pulley of the alternator to avoid damage to
stator and rectifier, or use a 11/8" O.E., Wrench on the adjustment lug of the alternator case casting.
5. Never attempt to polarize the alternator. Polarizing is not applicable to alternator and could damage
the regulator.
6. Observe polarity when installing a battery in aircraft. Reverse polarity will destroy the diodes in
alternator.
7. Always connect a booster battery in parallel, negative to negative, positive to positive.
8. Before disconnecting a booster battery, reduce engine speed to idle, operate taxi light. This will
prevent voltage surge that could destroy small light bulbs.
9. Disconnect the battery ground cable before connecting a charger to the battery.
CHECKING ALTERNATOR SYSTEM - ON AIRCRAFT.
VISUAL INSPECTION.
Prior to testing, a visual inspection of components of charging system should be performed. What
appears to be an authentic charging system problem, can in some instances be traced to some of the
discrepancies out-lined here that are relatively simple to correct.
1. Proper belt tension - if alternator pulley wheel can be slipped on belt by hand -the belt is too loose or
glazed - replace or tighten belt per specification.
2. Specific gravity of battery is 1.275 - fully charged battery.
3. Clean and tighten battery posts and cable clamps.
4. Clean and tighten wiring connection at alternator.
5. Clean and tighten wiring connections at regulator.
- NOTE-
Because of additional transistorized electrical components being
incorporated, a simplified voltmeter testing procedure is preferred
to prevent damge to other components. Follow test procedures as
arranged for systematic problem solving approach.
AMMETER PROVE-OUT TEST.
Place the "BAT' portion of master switch in the ON position (engine not running). Switch the landing
light switch ON. Ammeter should show discharge. If the ammeter needle does not move, check wiring
connections at ammeter are tight and clean, or ammeter is defective - replace ammeter.
EFFECTIVITY: FORD
24-32-05
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