Six ways to repair car circuit faults!

Six ways to repair car circuit faults!

A car is a large machine with many components and complex wiring, so how to deal with the miscellaneous wiring failures is an aspect that car maintenance personnel need to understand and master. The following is a simple analysis of common car circuits failures, seeking troubleshooting methods.
Common faults in the car circuit are broken circuits, short circuits, damage to electrical equipment, etc. To quickly and accurately diagnose the fault, the following are a few common repair methods.

Intuitive diagnosis

When the car circuit failure, sometimes there will be smoke, sparks, strange sound, scorching, heat and other abnormal phenomena. These phenomena can be directly observed so that you can determine the location of the fault.

Short circuit

Auto circuit breakage fault, you can also use the short circuit method, that is, using a driver or wire will be suspected of a circuit breakage fault short, observe the instrument pointer changes or electrical equipment working conditions, so as to determine whether the circuit breakage fault exists.

Break circuit

Auto circuit equipment overlap (short circuit) fault can be used to determine the disconnection method. The suspected overlap fault circuit section disconnected, observe the electrical equipment in the overlapping fault still exists, to determine the circuit overlap parts and causes.

The high-voltage test fire

High-voltage circuit latching test fire, observe the spark condition and determine the ignition system’s work. A specific method is:
Remove the ignition coil or spark plug high-voltage wire.
Align it with the spark plug or cylinder head, the distance of about 5mm.
Turn on the starter switch.
Turn the engine.
See the jumping fire.
If the spark is strong, sky blue, and jump fire sound, it indicates that the ignition system is working normally; conversely, it is not working properly.


Observe the car instrument panel ammeter, water temperature gauge, fuel gauge, oil pressure gauge and other indications to determine whether there is a fault in the circuit. For example, when the engine is cold, and the ignition switch is turned on, the water temperature meter indicates that the full-scale position is not moving, indicating that the water temperature meter sensor is faulty or the line has an override.

Circuit detector

Automotive circuit detectors can easily and accurately detect and diagnose various line faults in the car line, line aging; through the automotive circuit detector can quickly find out the possible faults, such as BT260, BT280, etc. can provide reliable information for troubleshooting.

Repairing car circuit faults
Repairing car circuit faults

Automotive circuit tester mainly detects the following information.
a. Component breakdown. Breakdown includes overvoltage breakdown or overcurrent, thermal breakdown caused by overheating, etc. The breakdown is sometimes manifested in the form of a short circuit. And sometimes in the form of a broken circuit. Due to circuit failure caused by overvoltage, overcurrent breakdown is often irrecoverable.
b. Component aging or performance degradation, This includes many aspects. For example, such as capacitor capacity reduction filial insulation resistance drop, transistor leakage increase, the resistance value of the resistance change, the adjustable resistance value can not be continuously changed, relay contact ablation. In addition, such components as relays are often due to insulation aging, coil burnout, inter-turn short circuit, contact jitter, and even the inability to adjust the initial action current failure.
c. Line failure. This type of failure includes wiring loosening, poor contact, moisture, corrosion, etc., resulting in poor insulation, short circuit, bypass, etc. This type of failure is generally not related to the components.

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