The air conditioner is on and the fan and compressor won't run. Check the AC voltage. If there are no lights showing on the thermostat, it is not receiving any 12-volt power. Check the 12-volt fuses. Check the AC voltage by plugging in to shorepower. Plug a voltmeter into an outlet and turn the air conditioner on. Wait a couple of minutes, then check the AC voltage. It should be over 103.5 volts.
If the compressor tries but won't start and the fan does run, check the voltage. Check for bad air flow, a dirty filter, dirty condenser, a leaking duct or, again, the AC voltage. If these aren't the problem, you may have to take the unit in to a mechanic to check the filters and condenser. The evaporator could freeze up by having poor air flow, short cycling or by having the fan on and the thermostat on a low setting.
If the air conditioner is leaking, a certified technician is necessary. He will check that it is mounted tightly and that the condensation holes aren't plugged. He'll also make sure the roof gasket is working properly. Perform do-it-yourself leakage repairs with caution. The solution could be dangerous and the machine should be shut off to avoid electrical shock.
