ELECTRICAL
10.18
CURRENT DRAW - KEY OFF
CAUTION: Do not connect or disconnect the battery
cable or ammeter with the engine running. Damage
will occur to light bulbs and speed limiter.
Connect an ammeter in series with the negative
battery cable. Check for current draw with the key off.
If
the
draw
is
excessive,
loads
should
be
disconnected from the system one by one until the
draw is eliminated. Check component wiring as well
as the component for partial shorts to ground to
eliminate the draw.
Current Draw - Key Off:
Maximum of .02 Adc (20 mA)
CHARGING SYSTEM “BREAK
EVEN” TEST
CAUTION: Do not connect or disconnect the battery
cable or ammeter with the engine running.
CAUTION:
Never use the electric starter with the
ammeter connected, as damage to the meter or meter
fuse may result. Do not run test for extended period
of time.
Do not run test with high amperage
accessories.
The “break even” point of the charging system is the
point at which the alternator overcomes all system
loads (lights, etc.) and begins to charge the battery.
Depending on battery condition and system load, the
break even point may vary slightly. The battery should
be fully charged before performing this test.
G
Connect an ammeter (set to DC amps)
in series between the negative
battery cable and terminal.
Do not use electric start.
--
+
YB14A
Current Drain Inspection
Key Off
Less Than 9 mA
G
Connect a tachometer according to
manufacturer’s instructions.
G
With engine off and the key and kill switch in the
ON position, the ammeter should read
negative amps (battery discharge). Reverse
meter leads if a positive reading is indicated.
G
Shift transmission into neutral. Start engine
with recoil only.
G
Increase engine RPM while observing ammeter
and tachometer.
G
Note RPM at which the battery starts to charge
(ammeter indication is positive).
G
With lights and other electrical load off, this
should occur at approximately 1500 RPM or
lower.
G
Turn the lights on and lock parking brake to keep
brake light on.
G
Repeat
test,
observing
ammeter
and
tachometer. With lights on, charging should
occur at or below 2000 RPM.
ALTERNATOR OUTPUT TEST
(AC AMP)
This test measures AC amperage from the alternator.
CAUTION: This test simulates a “full load” on the
alternator. Do not perform this test longer than required
to obtain a reading or the alternator stator windings may
overheat. Do not exceed idle rpm during this test.
To Calculate Available Alternator Output
150W
12V
=
12.5 Amps
I
=
P
E
I = Current in Amps
P = Power in Watts
E = Electromotive Force (Volts)
Alternator Current Output:
Minimum of 7 AC Amps
G
Maximum alternator output will be indicated on
the meter. It is not necessary to increase
engine RPM above idle.
G
Place the red lead on the tester in the 10A jack.
G
Turn the selector dial to the AC amps (A
µ
)
position.
G
Connect the meter leads to the wires leading
from the alternator (see schematic for proper
wiring colors).
G
Start the engine and let it idle. Reading should
be a minimum of 7A at idle.
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Summary of Contents for 2009 Trail Blazer 330
Page 94: ...ENGINE 3 48 NOTES P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 110: ...FUEL SYSTEM CARBURETION 4 16 NOTES P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 124: ...BODY STEERING SUSPENSION 5 14 NOTES P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 196: ...ELECTRICAL 10 4 REVERSE LIMIT SYSTEM P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 226: ...ELECTRICAL 10 34 NOTES P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 227: ...ELECTRICAL WIRING DIAGRAM 2009 TRAIL BOSS P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 228: ...ELECTRICAL WIRING DIAGRAM 2009 TRAIL BOSS P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 229: ...ELECTRICAL WIRING DIAGRAM 2009 TRAIL BLAZER P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...
Page 230: ...ELECTRICAL WIRING DIAGRAM 2009 TRAIL BLAZER P a r t S h a r k c o m 8 7 7 9 9 9 5 6 8 6 ...