Capacity Test; Charging System Tests; No Load, Load; Over Voltage - Ford VSG-411 Service Manual

4-02
Charging System
4-02
CAPACITY TEST
A high rate discharge tester (Rotunda Battery-Starter Tester
02-0204) or equivalent in conjunction with a voltmeter is used for
this test.
1. Turn the control knob on the Battery-Starter Tester to the off
position.
2. Turn the voltmeter selector switch to the 20-volt position and
test selector switch to "AMP".
3. Connect both positive test leads to the positive ( + ) battery
post and both negative leads to the negative ( - ) battery post.
The voltmeter clips must contact the battery posts and not the
high-rate discharge tester clips. Unless this is done, the actual
battery terminal voltage will not be indicated.
4. Turn the load control knob in a clockwise direction until the
ammeter reaches the applicable discharge rate specified in the
discharge rate table.
5. With the ammeter reading the required load for 15 seconds,
note the voltmeter reading. Avoid leaving the high discharge
load on the battery for periods longer than 15 seconds.
If the voltmeter reading is above the minimum specified in the
table with the test equipment for that temperature, the battery has a
good output capacity and will readily accept a charge, if required.
Check the state of charge.
If the voltage reading obtained during the capacity test is below
the minimum specified in the table, check the state of charge.
Battery Discharge Rates
Ampere
Hours
Discharge Rate
Amperes
I
45
I
190
I
I
53
I
200
I
I
63
I
260
I
I
68
I
235
I
I
71
I
235
I
I
85
--I
240
I
I
90
I
310
I
Temperature Correction Chart -
All Batteries
Temperature "F
I
Minimum Acceptable Load
Voltage
70 (or above)
9.6
60
9.5
50
9.4
40
9.3
30
9.1
20
8.9
10 8.7
0 8.5
CHARGING SYSTEM TESTS
When performing charging system tests, turn Off all lamps and
electrical accessories. Disengage engine load.
NOTE: Battery posts and cable clamps must be clean and tight
to ensure accurate meter indications.
BASE VOLTAGE
1. With ignition Off and no electrical load on, connect negative
lead of test voltmeter to negative battery cable clamp.
. 2. Connect positive lead of voltmeter to positive battery cable
clamp.
3. Record battery voltage reading shown on voltmeter scale (this
is called base voltage).
NO LOAD
1. Connect a tachometer to the engine.
2. Start engine and increase speed to approximately 1500 rpm.
With no other electrical load voltmeter pointer should move
upward (increase) but not more than 2.0 volts above base
voltage (the first recorded battery voltage reading). The read-
ing should be taken when the voltmeter pointer stops rising. It
may take a few minutes to reach this point.
If voltage increases the proper amount, go to Load Test. If
voltage increases over 2 volts, perform the Over Voltage
Tests. If voltage does not increase, perform Wiring Continuity
Test.
LOAD
1. With engine running.
2. Increase engine speed to 2000 rpm. Voltmeter should indicate
a minimum of 0.5 volts above base voltage.
If above tests indicate proper voltage readings, charging system
is operating normally. Use test lamp and check for battery drain.
OVER VOLTAGE
1. If voltmeter reading indicates more than 2 .O volts above base
battery voltage, connect a jumper wire between regulator base
and alternator frame. Repeat No Load Test. If over voltage
condition disappears, check ground connections on the alter-
nator, and from engine to frame and to battery. Clean and
tighten connections securely.
2. If over voltage condition still exists, perform Control Voltage
Test.
WIRING CONTINUITY
1. Disconnect the battery ground lead, then disconnect the alter-
nator wiring plug.
2. Inspect the terminals for signs of arcing.
3. Connect the battery ground lead and turn the ignition switch to
the "ON" position.
4. Connect a voltmeter between a good ground and each of the
wiring plug terminals in turn (Fig. 1). The voltmeter should
read approximate battery voltage at all terminals. If voltage
readings are correct go to Output Test. A zero reading indi-
cates an open circuit. Repair as required.
FIG. 1 Wiring Continuity Test
A - Alternator Wiring Plug
B- Voltmeter