How to check a short circuit with a Multimeter?

Use of an Ohm Meter is the best, and only way I can think of, to test any kind of short circuits. Since you used the Word track in the question I'm guessing this is a model train problem. The first thing to do is check the voltage at the transformer (electrical source). Then check the Ohms of each track. This will tell which track has the short. Moving one test lead up the track should locate the short. I the train doesn't move when the power is applied, the problem is probably a broker solder point.