Car electrical check
Required tools and materials:
* Multimeter
* Screwdriver
* Open-end wrench
* Jumper wires
* Vehicle wiring diagram (if available)
Verification steps:
1. Visual inspection
* Inspect electrical components such as wires, connectors, fuses and relays for signs of damage, corrosion or looseness.
* Make sure all connections are secure and not broken.
2. Checking battery voltage
* Set the multimeter to constant voltage (DCV) mode.
*Connect the red lead of the multimeter to the positive terminal of the battery and the black lead to the negative terminal.
*Normal battery voltage should be between 12.6 and 12.8 V with the engine off.
*If the voltage is below 12V, charge or replace the battery.
3. Battery load test
* Connect the multimeter to the battery as described above.
* Turn on the headlights or other electrical component to put a strain on the battery.
* The voltage should drop, but not below 9.6 V.
*If the voltage drops below 9.6V, the battery may be weak or discharged.
4. Checking fuses
* Using a screwdriver or open-end wrench, remove the fuses from the fuse box.
* Inspect fuses for burnt wires.
* Replace any blown fuses with fuses of the same rating.
5. Relay test
*Locate the relay in the car’s relay box.
*Use jumper wires to temporarily short-circuit the relay contacts corresponding to the positive power supply and control contacts.
* If a shorted relay causes a solenoid or other component to operate, the relay is good.
* If shorting the relay does not operate, replace the relay.
6. Checking electrical circuits
* Use a vehicle wiring diagram (if available) to determine the path of electrical circuits.
*Use your multimeter to set it to continuity mode (usually indicated by a “?” or “beep” symbol).
*Connect one lead of the multimeter to one end of the circuit and the other lead to the other end.
*If the multimeter beeps or shows low resistance, the circuit is complete.
* If the multimeter does not beep or shows high resistance, there is an open or short circuit in the circuit.
Adviсe:
* Check the car’s electrical system in a well-lit and ventilated area.
* Wear gloves and eye protection.
* Disconnect the negative terminal of the battery before starting any electrical work.
* If necessary, have more serious electrical problems diagnosed and repaired by a qualified auto mechanic.