Toyota Supra 1990 Manual page 376

•
CH-4 CHARGING SYSTEM - On-Vehicle Inspection
CH0464
Disconnect Wire
from Terminal B
~
'r-----te A
+
Alternator
Ammeter
- -------""'
"-
"
Battery
Terminal B
Voltmeter
CH0732
13.5 - 15.1 V
10A or Less
20 30
Voltmeter
Ammeter
CH0412 CH001 0
5. VISUALLY CHECK ALTERNATOR WIRING AND LISTEN
FOR ABNORMAL NOISES
(a) Check that the wring is in good condition.
(b) Check that there is no abnormal noise from the alter-
nator while the engine is running.
6. INSPECT DISCHARGE WARNING LIGHT CIRCUIT
(a) Warm up the engine and turn it off.
(b) Turn off all accessories.
(c) Turn the ignition switch to ON. Check that the dis-
charge warning light is lit.
(d) Start the engine. Check that the light goes out.
If the light does not operate as specified, troubleshoot the
warning light circuit.
7. CHECK CHARGING CIRCUIT WITHOUT LOAD
HINT: If a battery/alternator tester is available, connect
the tester to the charging circuit according to the manufac-
turer's instructions.
(a) If a tester is not available, connect a voltmeter and
ammeter to the charging circuit as follows:
• Disconnect the wire from terminal B of the alter-
nator and connect the wire to the negative (-) ter-
minal of the ammeter.
• Connect the test lead from the positive (
+ )
termi-
nal of the ammeter to terminal B of the alternator.
• Connect the positive
(+)
lead of the voltmeter to
terminal B of the alternator.
• Ground the negative (-) lead of the voltmeter.
(b) Check the charging circuit as follows:
With the engine running from idling to 2,000 rpm,
check the reading on the ammeter and voltmeter.
Standard amperage: 10 A or less
Standard voltage: 13.9 - 15.1 V at 25°C (77°F)
13.5 - 14.3 V at 115°C (239°F)
If the voltage reading is greater than standard voltage,
replace the IC regulator.