General information about electricity
If an electrical component such as the front light, rear light, indicators or meter is not working, the first thing to do is to check the wires. The wires should not be damaged or have exposed copper and there should be no extra wires loose. If any wire is exposed, replace it with a new one or cover it properly. If the wires are loose, find out if they should be loose and if not, reconnect them properly. If the wires show exposed copper (old bikes often do), you should not ride in the rain, as this can cause a short circuit.