Midtronics EXP-1002, Instruction Manual

Page: 18 / 32

Midtronics Inc. 7000 Monroe Street Willowbrook, IL 60527 www.midtronics.com
18
Chapter 3: System Test EXP-1002
Decision Action
NO
PROBLEMS
The system is showing normal output from the
alternator. No problem detected.
NO OUTPUT The alternator is not providing charging current
to the battery.
√ Check the belts to ensure the alternator is
rotating with the engine running.
√ Check all connections to and from the
alternator, especially the connection to
the battery. Clean or replace cable if
necessary and retest.
√ If the belts and connections are in good
working condition, replace the alternator.
(Older vehicles use external voltage
regulators, which may require only
replacement of the voltage regulator.)
LOW
OUTPUT
The alternator is not providing enough current
to power the system’s electrical loads and
charge the battery.
√ Check the belts to ensure the alternator is
rotating with the engine running.
√ Check the connections from the alternator
to the battery. If the connection is loose
or heavily corroded, clean or replace the
cable and retest.
HIGH
OUTPUT
The voltage output from the alternator to
the battery exceeds the normal limits of a
functioning regulator.
√ Check for loose connections and a
normal ground connection. If there are
no connection problems, replace the
regulator.
The normal high limit of a typical automotive
regulator is 14.5 volts +/–0.5. Refer to the
manufacturer specifications for the correct
limit, which may vary by vehicle type.
Diode Decisions
Decision Action
EXCESSIVE
RIPPLE
One or more diodes in the alternator are not
functioning or there is stator damage, which is
shown by an excessive amount of AC ripple
current supplied to the battery.
√ Make sure the alternator mounting is
sturdy and that the belts are in good
shape and functioning properly. If the
mounting and belts are good, replace the
alternator.
OPEN
PHASE
Replace the alternator.
OPEN
DIODE
SHORTED
DIODE