Quote Originally Posted by spaceorange12 View Post
...However, when I try to set the heatbed temp on the LCD I hear a click from the relay and the RAMPS restarts. Does this indicate a short circuit? I didn't think that heatbeds were polarity sensitive.
It could be a short, or it could be the heat bed is drawing more current than your power supply can handle and the power supply cuts out. Is your supply good for 30+ amps?

You are correct that heat beds are typically not polarity sensitive, and that's why the input wires are the same color. You're hearing a relay click, so I guess that means the heat bed doesn't have a MOSFET switch, which would make the input polarity important.