What Causes a Complete Vehicle Power Failure?
2 Answers
Complete vehicle power failure may be caused by a depleted battery, detached battery terminals, or burnt/damaged wiring, main fuse, or main relay. Connecting the vehicle to a diagnostic tool: Select an appropriate current clamp, connect the output end to the diagnostic tool, and after matching, access the current detection interface. Confirming connection direction: Verify the polarity connection direction of the current clamp; the current arrow should align with the actual current direction, ensuring the current clamp is fully closed. Confirming correct connection and powering off: After confirming the equipment is correctly connected, turn off the vehicle's power and lock it. Wait for the vehicle to enter sleep mode, then test the vehicle's quiescent current. If the quiescent current is excessively high or shows significant fluctuations, it indicates a vehicle leakage issue.
I've experienced a complete vehicle power failure several times, and it's quite troublesome. Common causes include an aging or dead battery, which may be due to reaching its lifespan or forgetting to turn off the lights for an extended period. Alternator failure is also critical—if it breaks down, the battery won't charge, leaving all electrical components dead. A blown main fuse can directly cut off the entire electrical system, usually caused by a short circuit or overload. Wiring issues, such as loose or corroded terminals, are more common in older vehicles. If the power fails while driving, the car may suddenly stall, which is very dangerous—immediately pull over and turn on the hazard lights. Prevention is key: I check the battery's condition monthly, clean the terminals, and replace parts when necessary to minimize surprises. Also, improper modifications to electrical equipment can easily cause problems, so it's best to visit a reputable repair shop—safety first.
