Finding short circuits
Z-GI-16spec tableShorts occur between the power (positive) and ground (negative) sides of a circuit. Therefore, finding a short circuit requires determining how the circuit is routed.
Circuits not connected to control unit
Examples and finding short circuit — circuits not connected to control unit
Short (A)
IndicationFuse melts.
Finding short circuit1. Remove the fuse and main fuse of the circuit. 2. Disconnect all connectors of electrical components in the circuit. 3. Attach a voltmeter or test lamp to the fuse box and reconnect each connector, beginning nearest the power source. 4. Check the voltmeter or see if the test lamp lights as the connectors are connected. A short has occurred where the voltmeter reading changes or the test lamp lights.
Short (B)
IndicationMain fuse melts.
Finding short circuit(see Short (A))
Short (C)
IndicationThe motor operates regardless of whether the ignition switch is ON or OFF when the ignition switch is ON. The fuse is not melted.
Finding short circuit(see Short (A))
Short (D)
IndicationThe main fuse melts when the ignition switch and thermo-switch are ON and the relay is operating.
Finding short circuit(see Short (A))
Circuits connected to control unit
Examples and finding short circuit — circuits connected to control unit
Short (A)
IndicationFuse melts.
Finding short circuit1. Remove the fuse and main fuse of the circuit. 2. Disconnect all connectors of electrical components in the circuit. 3. Attach a voltmeter or test lamp to the fuse box and reconnect each connector, beginning nearest the power source. 4. Check the voltmeter or see if the test lamp lights as the connectors are connected. A short has occurred where the voltmeter reading changes or the test lamp lights.
Short (B)
IndicationSolenoid A operates normally when the ignition switch is ON.
Finding short circuit(see Short (A))
Short (C)
IndicationThe CPU transistor burns out when the ignition switch is turned ON.
Finding short circuit(see Short (A))
Short (D)
IndicationThe CPU thinks the switch is ON because the same conditions exist as when the switch is ON.
Finding short circuit1. Attach the test lamp or voltmeter to the CPU connector. 2. Connect to the switch/sensor connector. 3. Check to see if the test lamp lights. A short has occurred where voltmeter reads 0V or the test lamp goes out.
Short (E)
IndicationThe CPU senses the sensor to be 0 Ω because the conditions exist as when resistance value is 0. The CPU equipped with the self-diagnosis function outputs the malfunction code.
Finding short circuit(see Short (D))