Two methods for multimeter to check circuit short circuit

Use a multimeter to check for short circuits-voltage detection method

Diagram of the method to check the short circuit of the car circuit with a multimeter

① Remove the burned fuse and disconnect all loads through the fuse power supply (ie SW1 is disconnected, and the relay and solenoid valve are disconnected).

② Turn the ignition switch to the ON or START position. Confirm that the battery voltage is on the positive side of the battery at the fuse port (one probe is placed on the positive side of the battery in the fuse box, and the other probe is placed at a known good ground).

③ Disconnect SW1, connect the multimeter probe across the two ports of the fuse to measure the voltage.

There is voltage, and the short circuit is between the fuse box and SW1 (point A);

No voltage, short circuit farther after SW1.

④ Close SW1, disconnect the relay and solenoid valve, and connect the multimeter probe across both sides of the fuse port to measure the voltage.

There is voltage, and the short circuit is between SW1 and the relay (point B);

No voltage, the short circuit is farther behind the relay.

⑤ Close SW1, and use a fuse jumper to connect the closed relay to measure the voltage.

There is voltage, and the short circuit is behind the relay circuit or between the relay and the open solenoid valve (point C);

No voltage, return to the inspection step and check the power supply of the fuse box.

Use a multimeter to check the circuit for short circuits-continuity detection method

① Disconnect the negative electrode of the battery and remove the blown fuse.

② Disconnect all loads through the fuse power supply (SW1 is disconnected, and the relay and solenoid valve are disconnected).

③ Connect one probe of the ohmmeter to the load side of the fuse port, and connect the other probe to a known good ground.

④ Disconnect SW1 and check continuity.

Conduction, short-circuit between the fuse and SW1 (point A);

No conduction, the short circuit is farther after SW1.

⑤ Close SW1, and then open the relay. Place the probe on the load side of the fuse port and a known good ground. Then check the continuity.

Conduction, short circuit between SW1 and relay (point B);

No conduction, the short circuit is farther behind the relay.

⑥ Close SW1 and use the jumper to connect the relay. Place the probe on the load side of the fuse port and a known good ground. Then check the continuity.

Conduction, short circuit between the relay and the solenoid valve (point C);

No conduction, check the solenoid valve.