Mitsubishi MOTORS Laser 1991, Service Manual, Page: 22 / 320

Power supply
Power supply
(Remove the fuse
light
A circuit consists of the power supply, switch, relay, load, ground,
etc. There are various methods to check a circuit including an
overall check, voltage check, shortcircuit check and continuity
check. Each of these methods is briefly described in the following.
(1) Ground one lead wire of the test light. If a voltmeter is
used instead of the test light, ground the grounding side
lead wire.
(2) Connect the other lead wire of the test light to the
power side terminal of the switch connector. The test
light should come on or the voltmeter should indicate a
voltage.
(3) Then, connect the test light or voltmeter to the motor
connector. The test light should not come on, or the
voltmeter
no voltage. When the switch
is turned on in this state, the test light should come on,
or the voltmeter should indicate a voltage, with motor
starting to run.
(4) The circuit illustrated here is normal but if there is any
problem such as the motor failing to run, check voltages
beginning at the connector nearest to the motor until
the faulty part is identified.
Because the fuse has blown, it is probable that there is a
short-circuited circuit. Follow the procedures below to
narrow down the short-circuit location.