If the relay does not light, it means that the relay may not work. Generally, the red light of the intermediate relay indicates AC voltage, and the green light indicates DC voltage. When it is found that the relay does not light, it is necessary to use a testing instrument to check the front end of the relay and itself.
1. Check if the wiring is loose
To troubleshoot, the first step is to cut off the power supply and start all the connection wires of the relay. Check whether the connection wires of each part are loose or poor contact occurs. If there is such a situation, fasten them in time and test if they are powered on again. Already normal.
2. Measuring whether the relay has voltage input
When all the connecting wires are normal, use a multimeter to measure whether the relay coil contact has voltage input and whether the value is normal. If five points are to be input, there is no voltage supply at the front end. For the time being, first eliminate the relay fault and find whether there is a problem with the front end voltage output.
If there is voltage input, but the light of the relay is still off, then there may be a problem with the relay coil, and it has not been operated. In this case, the ohm file of the multimeter is used to measure the coil, and the resistance is different for different models. Similarly, ranging from hundreds to thousands of euros.