What Causes a Car to Fail to Start on Rainy Days?

[LeLevi]

The reasons why a car fails to start on rainy days are as follows: 1. Short circuit: Since most of the vehicle's wiring and pipelines are concentrated in the engine compartment, driving through water can inevitably splash water onto the internal wiring and pipelines. Over time, this can easily lead to electrical short circuits and obstructed fuel lines, with the most direct fault being the car's failure to start. 2. Battery: In low temperatures, the car battery's electrolyte viscosity increases, reducing its permeability and increasing resistance, which lowers the output power. This makes it difficult for the starter to crank the engine, preventing it from reaching the minimum starting speed and affecting engine ignition. Additionally, the low terminal voltage of the battery results in weak sparks from the spark plugs. Combined with the increased resistance between electrodes due to the dense mixture, it becomes difficult to ignite the mixture, leading to engine starting difficulties.