One of methods of search of short circuit is extraction of a safety lock and connection instead of it of a lamp sampler or the voltmeter. Tension in a chain has to be absent. Pull conducting, watching a lamp sampler. If the lamp begins to blink, somewhere in a plait of wires there is a short circuit on weight which is perhaps caused by wear of isolation of wires. Similar check can be made for each of components of an electric chain by turning on of the corresponding switches.