Common Circuit Tests; Open Circuit Test; Short Circuit Test; Voltage Test - Husqvarna Z400 Series Service Manual

ELECTRICAL

Common Circuit Tests

NOTES:
• Check electrical connectors, harnesses, and battery
for loose or corroded connections prior to
performing electrical tests.
• For circuit information, see "Main Schematic" on
page 6-3.

Open Circuit Test

1. Disconnect electrical connector to be tested.
2. On the component end of the harness, connect the
jumper wire from the suspected terminal of the
electrical connector to the chassis ground.
3. Set multimeter to ohms.
4. With the key switch in the OFF position, connect the
meter lead to the terminal at the other end of the
circuit to the suspected electrical connector.
5. Connect the other meter lead to the chassis ground.
If resistance is more than 3 ohms, repair open circuit.

Short Circuit Test

1. Disconnect electrical connectors to be tested.
2. Set multimeter to ohms.
3. With the key switch in the OFF position, connect the
meter lead to the terminal at the component end of
the harness to the suspected electrical connector.
4. Connect the other meter lead to the chassis ground.
If resistance is more than 3 ohms, repair circuit.
5. Connect the meter lead to the terminal at the other
end of the circuit to the suspected electrical
connector.
6. With the other meter lead, check resistance across
all other terminals of electrical connector. If
resistance is less than 1000 ohms, repair circuit.

Voltage Test

1. Prepare machine for service. See "Prepare
Equipment for Service" on page 1-13.
2. Set multimeter to DC volts.
3. Connect the black lead from the meter to the battery
positive (+) terminal.
4. With the key switch in the ON position, connect the
red lead from the meter to the supply terminal of
component being tested.
NOTE: Electrical connector is connected to component
during test.
5. With the component switched on, check voltage. If
voltage is not within specification, repair circuit.

Ground Circuit Tests

NOTES:
• Check electrical connectors, harnesses, and battery
for loose or corroded connections prior to
performing electrical tests.
• For circuit information, see "Main Schematic" on
page 6-3.

Open Circuit Test

1. Disconnect electrical connector to be tested.
2. Set multimeter to ohms.
3. With the key switch in the OFF position, connect the
meter lead to the ground terminal of the main
harness of the electrical connector.
4. Connect the other meter lead to the chassis ground.
If resistance is more than 3 ohms, repair open circuit.

Voltage Test

1. Prepare machine for service. See "Prepare
Equipment for Service" on page 1-13.
2. Set multimeter to DC volts.
3. Connect the black lead from the meter to the battery
negative (-) terminal.
4. With key switch in the ON position, connect the red
lead from the meter to the ground terminal of
component being tested.
5. With the component switched on, check voltage. If
reading is between 0 and 1 volts, the ground circuit is
good.
6. If circuit is 0 or less or more than 1 volt, repair circuit.
6-18
Z400 Series