| 1. Disconnect tension from a chain and check a chain on integrity by means of a bulb with the connected power supply. |
| 2. Connect bulb wires by the chain ends (or to the positive end and mass of the car); if the control bulb lights up, in a chain there are no gaps. |
| 3. If the bulb does not light up, means, somewhere in a chain there is a gap. |
| 4. Precisely it is also possible to check the switch, having connected a control bulb to switch plugs. |
| 5. After turning on of the switch, the control bulb should light up. |