UNI-T UT108, Operating Manual

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UT108/109 OPERATING MANUAL
UT108/109 OPERATING MANUAL
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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 to the
DCV . Insert the red test lead into the A 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.