Troubleshooting: 1. The sound of the fan means that the impeller of the fan has friction sound. Just adjust the position of the fan. If this is not the case, loosen a small screw around the outside of the fan, tighten three slightly larger screws close to the fan motor! 2. If the battery car keeps driving, it is caused by relay damage or short circuit of plug connection. 3. If the outer cover cannot blow, first check whether the air volume of the fan is the whole vehicle and whether the fan mouth of the outer cover is tied well. 4. In the process of running the car, the speed key is slower than the whole car, and the belt on the motor is loose. It can be solved by tightening the large screw next to the motor. 5, can only move forward or back to check whether the reverse switch is adjusted correctly or whether the reverse switch is damaged. 6. I can't walk once. I stop for a while and then go. If there is music, I can't go: The battery has no electricity or the plug of the music box is loose. After the above problems may be ruled out, it is the problem of relay control switch. It is recommended not to change the 12V and 24V gears during driving of the two cars. The switch has been damaged during driving! Elaborate design, preferential price, considerate service and convenient and fast after-sales service aim to help users make brilliant achievements!