BRP Johnson J30TEL4SUA 2007 Service Manual page 88

ELECTRICAL
BATTERY CHARGING SYSTEM
Disconnect all wires from the fuse case. Check for
continuity between the white/red lead wire with the
plate terminal and the other two lead wires. If
there is no continuity, replace the fuse case.
Checking the Rectifier and Regulator
Resistance
The rectifier and regulator is a solid-state device
that cannot be reliably checked with resistance
tests. Instead, the engine must be run continu-
ously at approximately 3000 RPM in a test tank or
on a marine dynamometer while the system's
response to a partially discharged battery is moni-
tored.
IMPORTANT:
Before proceeding, check the bat-
tery voltage at the rectifier and regulator's white
lead wire. This will test the condition of the 25 amp
fuse and the wiring to the battery.
Disconnect the battery cables at the battery.
Connect a 0-40 amp ammeter in series between
the rectifier and regulator's white wire connector
(female) and the 25 amp fuse's white wire connec-
tor (male), or use an inductive pickup on the white
wire.
Connect the battery cables at the battery.
Connect a variable load tester (carbon pile)
across the battery terminals.
86
Excessive battery discharge rates might
overheat the battery, causing electrolyte
gassing and creating an explosive atmo-
sphere.
Start and run the engine at various speeds. Use
the variable load tester to draw the battery down
at a rate that is equivalent to the stator's full out-
put.
The ammeter should indicate the following out-
puts:
•
10 amps at 700 RPM
•
15 amps at 1200 RPM
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•
13 amps at 5000 RPM
Reduce the battery load toward zero amps. The
ammeter should indicate a reduced output. As the
current draw decreases, the battery voltage
should stabilize at approximately 14.5 volts.
If the results vary, check the condition of the stator
with a resistance test before replacing the rectifier
and regulator.
1
2
3
1. Stator
2. Rectifier and regulator
3. Ammeter
4. Jumper wire
5. 25 amp fuse
6. Starter relay
7. Red (+) battery cable
8. Carbon pile
WARNING
4 5
8
7
6
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