What is the reason for the Jetta fan not having high speed?
2 Answers
Jetta fan not having high speed may be caused by a malfunction of the electric fan. Electric fan malfunction: Normally, the electric fan has two gears, one is the low-speed gear, and the other is the high-speed gear. The high-speed gear usually works when the air conditioning pressure is too high or when the engine's water temperature reaches 103 degrees Celsius. The low-speed gear is just the opposite. The high-speed fuse of the electric fan is located in the fuse box above the battery. If the fuse is blown, the fuse line is not in good contact, the air conditioning high and low pressure switch is damaged, or the fan high-speed relay is damaged, it will cause the electric fan to have no high speed. Solution: It is recommended to go to the 4S store for repair. You can replace the fuse or reconnect the fuse line.
I've been driving a Jetta for over ten years, and recently noticed the fan only runs at low speed without high speed. Spent quite some time troubleshooting the issue. After checking, I found the common root cause might be a blown fuse—just replace one in the fuse box and it should work. It could also be a stuck relay; try shaking it to see if there's a clicking sound. If no sound, it needs replacement. If the fan motor is aging with rusted bearings, it might barely work at low speed but fail at high speed—take it apart and clean any dust stuck in the blades. Loose or corroded wiring connections can block current flow, so sand the plugs with sandpaper. When temperatures are too high, the fan won't run at high speed, and the engine might overheat—especially dangerous in summer traffic jams. My suggestion is to check the fuse first before investigating other issues. Don’t wait until a major breakdown occurs—fixing it early saves hassle and money.
