I was using bush trimmers and I accidentally cut the brown wire on my ac unit in half. I think it connects to the thermostat inside the house. How can I reconnect the colors and which colors goes to which?

First thing is to kill the power to the entire unit. If you cut the wires the colors should still match, cutting one brown wires leaves you with two brown wires. Just bare some copper and wire not the same color to the same color. Since this is outside you should use a water proof wire nut. http://www.cast-lighting.com/product...cessories/127/