Alternator; Alternator Testing Procedure - Holiday Rambler Imperial 2008 Owner's Manual

A Single Pole
Single Throw relay
(SPST) is an electro-
magnetic switch
consisting of a coil
(terminals 85 & 86),
one common terminal
(30), one normally
Single Pole Single Throw
closed terminal (87a),
Relay.
and one normally
open terminal (87).
When the coil of the relay is at rest (not
energized) the common terminal (30) and the
normally closed terminal (87a) have continuity.
When the coil is energized, the common
terminal (30) and the normally open terminal
(87) have continuity.
NOTE:
When there is power applied to the coil,
the coil sets up a magnetic field in the
windings. When the power is removed,
the field collapses. A momentary high
voltage discharge will occur. This is how
an ignition coil works.

ALTERNATOR

The function of the alternator is an electrical
system voltage maintainer, not a battery charger.
When the engine is operating, the alternator
maintains electrical system voltage relative to a
load, such as headlights and windshield wipers.
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When a heavy load is placed on the alternator,
such as trying to charge dead house batteries,
the operating temperature of the alternator will
increase. Excess operating temperature of the
alternator for extended periods of operation can
lead to premature failure of the alternator.
The alternator replaces amp hours the chassis
battery used to start the engine. The amount of
charge the alternator sends to the chassis battery
is dependent on the amount of time the engine
is operated. Repeatedly starting the engine for
short periods may not be enough operating time
to adequately replace the amp hours the chassis
battery uses to start the engine.
When traveling, keep an eye on the
voltmeter in the dash area. Normal readings
should be between 13 to 14.5 Volts DC.
Voltage indications higher or lower indicate a
potential problem with the charging system.
If the alternator output drops below an
acceptable level, a charge indication warning
lamp will illuminate.
NOTE:
The alternator is not designed to charge
the house batteries from a complete
discharge to a full state of charge. The
alternator will maintain the battery
charge during travel, supplying the DC
current necessary to operate running
lights or other DC loads.
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20 0 8 I M P E R I AL
ELECTRICAL SYSTEMS - CHASSIS — 9
200 Amp Alternator
If the house batteries are in a low state of
charge, it is recommended to charge the house
batteries with the inverter or an auxiliary battery
charger before driving the motorhome.
CAUTION:
Long-term use of the inverter to
operate the microwave while in transit
will damage the alternator. Use the
generator to operate the microwave
while in transit.

Alternator Testing Procedure

Alternator Testing:
Check all wiring for burnt or loose
electrical connections. Repair as needed.
Check all grounds and electrical connections.
Confi rm they are clean and tight.
- Alternator ground to chassis frame.
- Motor block ground to chassis frame.
- Chassis battery ground to chassis frame.
- Alternator positive output to isolator
relay terminal.
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