There are several reasons may cause this problem as following.
1. Check if the cigarette lighter plug is tightly connected to the cigarette lighter socket. Sometimes it is loose;
2. Check whether the car engine is started. If it is not started, it may be caused by insufficient power supply of the car battery;
3. Check if the power cord is damaged and cannot conduct electricity;
4. Consult the car manufacturer to see if the car's power supply has overload protection. The current output of the cigarette lighter plug of some cars is relatively low. When the current is slightly larger during work, the air pump will stop working and can be operated again when plugged in.
5. Desired tire pressure value is too high and beyond the tire inflator can reach.
6. If none of the above questions are true, unplug the power supply and insert it. If it still does not work, the air pump may be damaged and cannot work.
