Air Conditioning - central air unit stopped working

I have 2 central air units. Last night my sone was weedeating around the unit for the upstairs. He caught a wire that goes from the unit into the house. The wire is not cut between the unit and the house. I took the panel off both units. The wire is the same on both units. Question: Could the wire that goes in to side of the house 1. where does it go?? 2. could it have gotten unplugged making the unit not work?? thanks for any help.
It is now getting cold and the units fan is used to moved the heat thru the ducts.

If he "caught" the wire with the trimmer, it is possible that even though the wire does not appear to be damaged, the copper conductor inside the wire has been broken.

Like said check the 24 V wire to the unit. Turn the power off to the inside unit till you find it. If not you can short out the transformer inside or it can be out now. If the indoor fan can run the transformer is still good. So turn the power off till you fix the wire.
You dont say what you have there. Can be you have a small fuse on the 24V set up also that is bad.
ED

I have an Alpine unit. The fan is outside. Where would the fuse be?? Can the wire be ohm'd or checked from the thermostat in the house?
thanks

You could try this turn all power offinside and for out. Set tstat to call for AC. Ohn the tstat wires at the outdoor unit. that will tell you if good or not.