Midtronics EXP-802, Instruction Manual

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Midtronics Inc. 7000 Monroe Street Willowbrook, IL 60527
www.midtronics.com
14
EXP-803 Chapter 4: System Test
The System Test first evaluates the battery, then the
starting and charging systems.
IMPORTANT: When you start a new test, the last test
results in memory are overwritten. Remember to re-
cord or print the results if you need to retain them.
Battery Test
The System Test includes a test of the battery to eliminate it
as the cause of starting or charging problems. See the Battery
Test chapter for details.
Starter System Test
The performance of the starter and charging systems depends
on the battery’s condition. It is important that the battery is
good and fully charged before any further system testing.
1. In the Main Menu select the System Test icon.
2. Start the engine when prompted. If after the vehicle starts
and the results do not appear after approximately 25 sec-
onds, press NO START.
3. The analyzer displays one of five decisions and the results
in a series of screens.
NOTE: In some cases, the analyzer may not de-
tect the vehicle’s starting profile and display the
soft key options STARTED and NO START. If you
select STARTED, the analyzer skips to the Charg-
ing System Test. If you select NO START, the test
process ends.
Starter System Test Results
The results include the battery analysis. Use

or

to scroll
to each screen. See the Starter Test decisions table for an
explanation of the various Starter System test results. To
continue testing, press NEXT.
Starter
decision
Average
cranking
voltage
Cranking
time in mil-
liseconds
X axis = time
Starter System Decisions
Decision Action
CRANKING
NORMAL
The starter voltage is normal and the battery is
fully charged.
LOW
VOLTAGE
The starter voltage is low and the battery is
fully charged.
CHARGE
BATTERY
The starter voltage is low and the battery is
discharged. Fully charge the battery using a
Midtronics Diagnostic Charger and retest the
starter system.
REPLACE
BATTERY
Replace the battery and retest before testing
the alternator test..
NO START The engine did not start and the test was
aborted.
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 NEXT to continue.
NOTE: If necessary the analyzer will ask if you are
testing a diesel engine. It will resume testing after
you make your selection.
3. REV ENGINE WITH LOADS OFF FOR 5 SECONDS: Rev the en-
gine 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 NEXT.
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.
Chapter 4: System Test