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BT780 Battery Analyzer User’s Guide - English Version_V3.00
3.4 Charging System test
Once you have completed an in-vehicle test, the display alternates between the battery test
results and the message press
ENTER
for charging test. Press
ENTER
to proceed with the
charging test.
To start charging system test:
1. Follow the on-screen prompts to Rev the engine.
2. Turn on high beams headlights and the blower fan.
3. Rev engine with loads on.
4. Idle engine and turn off loads.
5. The Charging System decision is displayed at the end of the procedure.
No.
Test Results
Interpretation
1
NO PROBLEMS
System is showing normal output from the alternator.
2
NO OUTPUT
No alternator output detected.
Check all connections to and from the alternator, especially
the connection to the battery. If the connection is loose or
heavily corroded, clean or replace the cable 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.)
3
LOW OUTPUT
Alternator not providing sufficient to power the system's
electrical loads and charge the battery.
Check the belts to ensure the alternator is rotating with the
engine running. Replace broken or slipping belts and retest.
Check the connections from the alternator to the battery. If
the connection is loose or heavily corroded, clean or
reparable the cable and retest.
4
HIGH OUTPUT
Alternator voltage output exceeds the normal limits. Make
sure there are no loose connections and the ground
connection is normal. If there are no connection problems,
replace the regulator. Most alternators have a built-in
regulator that requires replacing the alternator. In older
vehicles that use external voltage regulators, you may need
to replace only the voltage regulator.
5
EXCESSIVE
RIPPLE
Excessive AC ripple detected.
One or more diodes in the alternator are not functioning or
there is stator damage.
