Generally caused by two reasons, the power of the vehicle air pump is too large, which should be compared with the power supply requirements of the cigarette lighter.
On the other hand, the cigarette lighter or the car air pump plug has a bad contact, and the circuit cross-sectional area is too small. You can take other small power consumption plug in to try, if it is still hot, it means that the power supply of the cigarette lighter is wrong, which must be repaired well, so as not to cause circuit failure, serious will cause spontaneous combustion. If it is not hot, it is the problem of the car air pump, then do not use it. If you look carefully, it looks like there are many words, but you can operate it easily.