Carrier 69GL15-114, Операция и обслуживание

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4-8
4.8 SERVICING THE ALTERNATOR
4.8.1 Preliminary Checks and Tests
NOTE
Before starting the actual electrical test
procedure, the charging system, battery and
wiring should be checked to eliminate possible
problem areas. Figure 1-8 identifies the
terminals on the rear of the alternator.
a. Check the condition and adjustment of belts.
1. Check belt adjustment
(refer to section 4.4).
2. Replace any worn or glazed belts.
b. Check to see that all terminals, connectors and
plugs are clean and tight.
1. Loose or corroded connections cause high
resistance and this could cause overcharging,
undercharging or damage to the charging system.
2. Badly corroded battery cables could prevent
the battery from reaching a fully charged condition.
c. Check battery condition and charge if necessary.
A low or discharged battery may cause false or misleading
readings when conducting in-unit tests.
4.8.2 Test Tools
A list of the following tools is provided to perform
tests on the alternator and its components.
1. Volt-ohm meter
2. Single-pole, single throw switch
3. 12 vdc lamp
4. Insulated 12 gauge stranded wire
5. Alligator clamp terminals
4.8.3 Problem Area Determination
CONDITIONS: Engine running for all tests
(unless otherwise specified).
a. Battery Undercharged
1. Perform open diode-trio test. (Refer to section
4.8.4, Test No. 1)
2. Perform regulator tests. (Refer to section 4.8.4). If
regulator is O.K., the cause is probably an open field
circuit, and alternator must be removed for repair.
3. Further investigation requires alternator removal
and repair (diodes).
b. Battery Overcharged
1. Perform alternator output test.
(Refer to section 4.8.4, Test No. 3)
2. Regulator shorted. Replace regulator.
4.8.4 In-Unit Alternator/Regulator Tests
Test No. 1 --- Open Diode-Trio Test
VOLTS
+ ---
d d
+
D+
B
A
JU1
*
12vdc
TEST LAMP
TOGGLE
SWITCH
BATTERY
AC TAP
(TACH.)
GROUND
EXCITE
INTEGRAL
REGULATOR
POS+
OUTPUT
(B+)
BATTERY
BLACK
RED
STEP TEST POINT INDICATION
1
2
3
A (B+)
B (REG)
BATTERY
VOLTAGE
1.5 TO 3.0 VOLTS
WITH TEST LAMP
ON
13.5 TO15.0 VOLTS
(JUMPER ATTACHED EN-
GINE RUNNING)
A (B+)
*
*
JUMPER NOT ATTACHED
(TO OIL PRESSURE
SWITCH OR
TOGGLE SWITCH )
+ ---
Figure 4-8. Open Diode-Trio Test
CONDITIONS: Start-run-stop switch (SRS) in RUN
position and engine stopped (after proper hook-up is
made and test leads connected). No electrical loads.
a. With jumper not attached. Check for battery
voltage at terminal A and for 1.5 to 3.0 volts at terminal B,
see Figure 4-8.
b. Add jumper JU1 between terminals A and B. Start
engine and run with no load. If the test lamp now goes off,
and charging voltage is present at terminal A (more than
battery voltage), the diode-trio is open. Alternator
should be removed for repair. If the voltmeter indication
is not in this range, remove the jumper and proceed to the
regulator test (test no. 2).