Surtek MUL04, User Manual

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E N G L I S H •
User's Manual
DIAGNOSIS OF AUTOMOTIVE TROUBLES
The digital multimeter is a tool for the very effective diagnosis of the troubles with
the electronic systems of the automobile. This part gives a special introduction
as to how the multimeter is used to diagnose any trouble with a fuse, switch,
solenoid, relay, starting and charging systems, ignition system, fuel system and
engine sensor..
1. FUSE TESTING: CHECK THE FUSE TO SEE IF IT IS BLOWN OUT
a. Set the rotary switch to 200 Ω.
b. As prompted at the LCD connect terminal, insert the red test lead into the Ω
terminal and the black one into the COM terminal..
c. Short circuit the red and black test lead probes, when the reading of the meter
should be displayed between 0.2 Ω and 0.5 Ω If it is more than 0.5 Ω, check the
test leads to see whether they are well connected.
d. Connect the red and black test lead probes in parallel to the two ends of
the fuse, when the reading of the meter should be displayed less than 10 Ω,
indicating that the fuse is good. When the display is overload “1”, it is shown
that the fuse has been blown out.
• It must be replaced with a fuse of the same type and size.
2. SWITCH TESTING: CHECK THE SWITCH TO SEE IF IT CAN WORK CORRECTLY.
a. The same as in Items 1 to 3 (Fuse Testing).
b. Connect the black test lead probe to one end of the switch and the red one to
another end. When the switch is connected, the reading of the meter should
be displayed less than 10 Ω. When the switch is cut off, overload “1” should
be displayed as the reading of the meter..
3. SOLENOID OR RELAY TESTING
a. The same as in Items 1 to 3 (Fuse Testing).
b. Connect the red and black test lead probes in parallel to the two end of a
solenoid or relay. The impedance of most of solenoids or relay coils is less than
200 Ω (See the details in the automotive manual.).
WARNING:
• Both ends of a general solenoid or relay are connected with diodes.
• Check to see if there is any damaged coil. Even if the coil is found satisfactory,
the solenoid or relay may still be damaged. The relay may be welded or worn
due to the frequent sparking of the contacts. The solenoid may be stuck when
the coil is in an on-position. Therefore some potential problems cannot be found
in testing.
4. STARTING/CHARGING SYSTEM TESTING
The on-off package of the engine starting system consists of a battery, engine
starting button, solenoid and relay starting buttons, lead connections and lines.
During the operation of the engine, the charging system keeps the battery charged.
This system consists of an AC generator, voltage calibrator, lead connections and
circuits. The multimeter is an effective tool for the checking of these systems.
1. Load-Free Battery Testing
Before testing the starting/charging system, test the battery to see if it is fully
charged.
a. Set the rotary switch to 20 VDC.
b. As prompted at the LCD connect terminal, insert the red test lead into the V
terminal and the black one into the COM terminal.
c. Turn off the ignition switch.
d. Turn on the driving lights for 10 sec. to release charges from the battery.
e. Connect the black test lead probe to the negative pole of the battery and the
red one to the positive pole of the battery.