System Connections; Generator Connections; Electrical Testing Precautions; Output Voltage Test - Ford VSG-411 Service Manual

04-6 Charcring System 04-6
DIAGNOSIS AND TESTING (Continued)
BATTERY DISCHARGE RATES
Ampere Hours Discharge Rate Amperes
45 190
53
200
63 260
68 235
71 235
85 240
90 310
TEMPERATURE CORRECTION CHART -
ALL BATTERIES
Temperature
Minimum
Acceptable
"C "F
Load Voltage
21
70 (or above) 9.6
16
60
9.5
10
50
9.4
4
40 9.3
-1 30 9.1
-7 20 8.9
-12 IO 8.7
-18 0 8.5
System Connections
Check that all charging system connections, cables, and
wires are sound, clean, and tight. This includes:
l
Battery cables
l
Battery connections
l
Starter solenoid connections
l
Starter ground
l
Regulator terminal connections
l
Generator wiring harness
Generator Connections
1.
Check all the harness connections to the generator.
Make sure they are clean and tight.
2. Inspect the soldered connections to the output diode
and the ground diode. These connections are visible
through the ventilation holes in the rear housing of the
generator.
Electrical Testing Precautions
Observe the following precautions to avoid permanent
damage to the regulator or to the generator diodes:
1. Do not disconnect the generator output lead, the
ground lead, or the battery cable while the engine is
running.
2. Do not disconnect the generator field terminal or the
regulator connection while the engine is running.
3.
Do not short the generator field terminal or field lead
to ground.
4. Disconnect the battery ground terminal before
removing the generator or the generator brush holder
assembly.
5. Never reverse polarity when charging or replacing the
battery.
Output Voltage Test
Perform this test if the trouble symptom is a warning light
indication while running, or a no-voltage indication on the
voltmeter. This test will check the generator output to verify
that the problem is in the charging system and not in the
instrument circuit. If the regulator is hot, do not perform this
test until the regulator has cooled down. The regulator will
respond to, and regulate at, a lower voltage as the
temperature rises. This offsets the tendency toward battery
overcharging in warm weather. This built-in temperature
compensation reduces generator output by about one volt
per 55°C (lOOOF) temperature rise.
1. Key OFF.
2. Check the voltage at the generator output terminal. It
should be battery voltage.
3. Start the engine.
4.
With the engine running at 1000 to 1200 rpm, check
the voltage at the generator output terminal. The
voltage should rise to 13.6 to 14.4 volts as soon as
the starting discharge has been restored.
GENERATOR
VOLTMETER