air conditioner clutch engages sporatically why
your blower has a short or there is power getting through ur resistor when it is not supposed to
Crumbob is correct,or could be low freon causing this issue.
Ford products also turn on the A /C compressor if the mode on the heater is in any position above heat on the floor, so if you turn it to defrost then the A/C will cycle intermittently, Ford did this to help dry the air to help with fogging the windows inside, I would suggest putting the heater in the floor mode only and watch the compressor, chances are it won't cycle in this mode.
Looking for a Used Mystique in your area?
CarGurus has 58 nationwide Mystique listings and the tools to find you a great deal.
Search Mercury Mystique Questions
Mercury Mystique Experts