What is the most likely cause if fluid is not spraying from the driver's side of a windshield washer system?

If fluid is not spraying from the driver's side of a windshield washer system, a kinked or blocked hose is the most likely cause because this directly prevents washer fluid from reaching the nozzle intended for the driver’s side. Over time, hoses can become crimped or pinched, restricting fluid flow. A blockage can occur due to debris or freezing if the washer fluid was not designed to handle cold temperatures, thereby blocking the path for the fluid to spray onto the windshield.

In contrast, a blown fuse would affect the entire washer system rather than just one side. No voltage at the pump could similarly lead to a complete failure of the washer system instead of isolating an issue to one side. Low fluid level could lead to inadequate spraying but would typically affect both sides of the system if they are drawing from the same reservoir. Thus, a kinked or blocked hose specifically accounts for the localized issue at the driver's side.