How to measure a short of power amplifier in car?
While I am not sure exactly what you have done (pictures or a schematic would be helpful) I do know that you can measure if two wires are connected by using the method you described. However, the best way to check this is with a continuity checker. If the ohmmeter you bought can also measure other things, I would read the instructions to see if it can also measure continuity. If you live near a harbor freight, they sell multimeters with this option for about 5 bucks. They also sell continuity checkers for a little less. If you plan on doing electronics much in the future I would definitely invest in a multimeter with a continuity checker. They are nice because you just place the probes on the two nodes you are interested in and it will audibly beep if the two nodes are connected.
Hope this helps!