[Z-linkCobra]

How old are the units? For a really simple fix....on the outside unit there is are two wire going to it. Little bitty wires that control the low voltage side of the contactor for the compressor. They will probably be together in like a brown outer insulator. They should run right along the refrigeration lines running out to the unit. Its the ones that always get cut with the weedeater in the summer time...lol.

Pull the cover off the unit and find where they are wire nutted to the wires coing from the unit. youll see the connection with two little white or blue wire nuts most times. If you take one of the wires loose and put the wire nut back on thw wire coming from the house...the outside unit wont run no matter what mode its in. That operates the contactor for the unit outside.

Its low voltage 24v so it wont hurt you if you touch it. try not to let touch ground...kind hard on transformers.

Thats the easiest cheapest way to fix it right now.