Charging System Voltage Testing - UNI-T UT105 Operating Manual

Measurement Operation(17)
H.Charging System Voltage Testing
This testing is used to see if the charging system operates
normally so as to provide the electronic systems with
adequate power (lamps, electric fans, radio sets, etc.).
1. Set the rotary switch of the multimeter to the 20VDC
As prompted at the LCD connect terminal,
insert the red test lead into the V terminal and the
black one into the COM terminal.
2. Connect the black test lead probe to the negative
pole of the battery and the red one to the positive
pole of the battery.
3. Run the engine idle and close or turn off all the
accessories with the normal voltage readings being
13.2 V to 15.2 v.
4. Open the throttle and control the rotation speed of
the engine between 1800 RPM and 2800 RPM. The
voltage readings should be consistent with those in
(3) (with the difference being no more than 0.5 V).
5. Turn on the lamps, windshield wipers, fans and so
on to increase the loads of the electronic systems
with the voltage readings being no less than 13.0 V.
6. If the readings in Steps 3., 4. and 5. are normal, the
charging system is also normal. If the readings in
Steps 3., 4. and 5. are beyond the limits or inconsistent
with those in the operation manual, check the current
ranges of the conveying belt, regulator, AC generator,
connector and open-circuit AC generator. If any further
diagnosis is required, refer to various kinds of automotive
manuals.
Model UT105: OPERATING MANUAL
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