GR8-1200 OEM
Midtronics Inc. 7000 Monroe Street Willowbrook, IL 60527
www.midtronics.com
29
Chapter 6: System Test
Charging System Test
When you press NEXT in any test result screen, the analyzer
proceeds to the Charging System Test.
1.
CHECKING FOR ALTERNATOR OUTPUT: The analyzer is test-
ing for alternator voltage.
2. TURN ALL VEHICLE LOADS OFF, IDLE ENGINE: Turn off ve-
hicle loads (blowers, interior light, radio, etc.) and idle the
engine. Press the NEXT soft key to continue.
3. REV ENGINE WITH LOADS OFF FOR 5 SECONDS: Rev the
engine with the loads off . Gradually increase the rpm until
the analyzer tells you to HOLD the rev level as the bar on
the display moves to the right.
NOTE
:
Some 8-cylinder and older vehicles idle at
a high level after starting, allowing the analyzer
to detect the rev automatically.
4. ACQUIRING DATA....HOLD ENGINE RPM: Continue to hold
the rpm while the analyzer takes system measurements.
5.
ENGINE REV DETECTED, IDLE ENGINE: The analyzer has de-
tected the rev. Press the NEXT soft key.
6. TESTING ALTERNATOR AT IDLE, LOADS OFF: The analyzer
will next test the engine at idle for comparison to other
readings, and then test the diode ripple. Excessive ripple
usually means one or more diodes have failed in the alter-
nator or there is stator damage.
7. TURN HIGH BEAMS AND BLOWER MOTOR ON, IDLE EN-
GINE: After a few seconds, the analyzer will ask you to turn
on the accessory loads. It will determine if the charging
system is able to provide enough current for the demands
of the electrical system.
I
MP
ORTANT
!
Turn on the high-beam headlights and the blower to
high. Do not use cyclical loads such as air conditioning
or windshield wipers.
8. TESTING ALTERNATOR AT IDLE, LOADS ON: The analyzer
will determine if the charging system is able to provide
suffi
cient current for the demands of the vehicle’s electri-
cal system.
9. REV ENGINE WITH LOADS ON FOR 5 SECONDS: The ana-
lyzer will test the charging system with the loads on and
prompt you to rev the engine. Gradually increase the rev
until the analyzer tells you to HOLD the rev level as the bar
on the display moves to the right.
10. ACQUIRING DATA....HOLD ENGINE RPM: Continue to hold
the rpm while the analyzer takes system measurements.
11. ENGINE REV DETECTED, IDLE ENGINE: The analyzer has de-
tected the rev. Press the NEXT soft key.
12. ANALYZING CHARGING SYSTEM DATA: The analyzer is
completing its fi nal analysis of the charging system data.
13. TURN OFF LOADS AND ENGINE: Press the NEXT soft key to
display the results.
Charging System Test Results
Screen 1 of 3
Decision
Loads-off
DC voltage
at rev
Loads-off
current at
rev
if amp clamp
is used
Loads-on
DC voltage
at rev
Loads-on
current at
rev
if amp clamp
is used
Screen 2 of 3
Normal DC
voltage
range
Bar graph of
DC voltage
within
normal
range (loads
on and off)
Screen 3 of 3
Graph
of diode
waveform
Peak-to-peak
AC voltage
.
