How to repair the car horn when it fails?

Release Time ：

2022-12-21

Check whether the live wire has power. Use a screwdriver to scrape the "battery" terminal of horn relay and ground. If there is no spark, it means there is an open circuit in the live wire. Check whether there is an open circuit in the circuit from the battery fuse to the "battery" terminal of the horn relay

How to repair the car horn when it fails?
1、 Check whether the live wire has power. Use a screwdriver to scrape the "battery" terminal of horn relay and ground. If there is no spark, it means there is an open circuit in the live wire. Check whether there is an open circuit in the circuit from the battery fuse to the "battery" terminal of the horn relay.
2、 If the live wire has power, use a screwdriver to short circuit the "battery" and "horn" terminals of the horn relay. If the horn still does not sound, it indicates that the horn is faulty; If the horn sounds, it means that the horn relay or button is faulty.
3、 Press the horn button and listen for any sound in the relay. If there is a "cluck" sound (contact closed), but the horn does not sound, it means that the relay contact is oxidized or ablated. If there is no "rattle" response in the relay, use a screwdriver to short the horn button terminal to the ground. At this time, if the relay contact is closed and the horn sounds, it means that the button is oxidized, rusted or dirty and the contact is poor; If the relay contact still cannot be closed and the horn still does not sound, there is an open circuit in the relay coil.
4、 When the button is pressed, the horn will not sound after only a "ho" sound. This fault is inside the horn. You can remove the horn cover and press the button to observe whether the horn contact is open. If it cannot be opened, readjust it; If it can be opened, check the contact gap and whether the capacitor or arc extinguishing resistor is short-circuited.
5、 If the horn does not sound when the button is pressed, check the circuit. If the fuse is disconnected (or the fuse is blown), first check whether there is a short circuit fault such as grounding in the circuit. The method is to string a test lamp at both ends of the disconnected fuse. If the test lamp is on, there is a grounding point in the circuit from the fuse to the horn relay; If the test light is not on, press the button again. If the test light is on again at this time, there is a grounding point in the circuit from the relay to the electric horn. Then use the open circuit method to find the grounding point for troubleshooting.