Thanks for the well focused diagram, it is exactly what I needed.
Use the multi meter to see if you get a high voltage read across the two wires at the disconnect switch on the outside unit. It is mounted on the unit, or on the wall next to the unit.
If you have power there look for the high pressure safety cut out switch..it is mounted inside the unit, in the electrical controls box... and sometimes you have to remove the sheet metal cover over the area where the power wires enter to unit to get to it.
Most times however there is a 1 inch diameter hole punched into the cabinet of the unit, with the reset button hidden about a half inch inside the hole. Press that button.
If you have the thermostat set on cooling, and it starts, then that was the problem. If you hear just the compressor starting, but the fan on top does not start, then the fan motor needs to be replaced most likely.
If the entire unit starts, including the fan turn the system off at the disconnect switch, then use a hose pressed against the finned condenser coil and blast all of the dirt out from between the fins, make sure you do not get fan motor inside wet.
When it dries out, turn the power on again to the unit, It should be OK for the day.
Then go shopping and buy 3 cans of foaming air conditioner condenser coil cleaner kit... and use it to clean the coil.
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