[Richard]

Ok.

First, set the thermostat to Fan. Does the internal fan come on? If not, check capacitor for evaporator motor. If that is good, the fan motor needs R&R. If the evap fan does not come on, the coils will ice up, the compressor will see high head pressure, overheat and possibly trip the breaker.

If the fan comes on, then set the tstat to high cool. Does the outside fan come on? If not, same drill as above.

If the outside fan comes on, then it's time to suspect the compressor.

As Tom said, open the bay door and stare. The controls access panel will be on the right of the unit. There is one screw at the very bottom. Remove the screw and hook something in the panel opening to pull outward. They are TIGHT. Now you are looking at the control circuit board. There will be a schematic on the back of the metal door you just removed.

Take a glance at the board for any burned spots or connections. There are know deficiences with this board.

This is where you will measure the amps on the compressor. Find the two leads going to compressor 1, and hang the ammeter around one of them. It should pull about 11 to 13 amps. If it pulls more, like over 20, then the rotor is locked and the comp will have to be replaced. If it doesn't pull anything, then more investigation is required. Disconnect the plug at the board and ohm the two leads to each other, and to ground. What readings do you get?

The caps are found behind that board. Look for four 1/4 nuts in the corners of the just outside the circuit board. Remove those, and slide the board out. You have to hold your mouth right to get it to come out. Now you see the caps. The big one is for the compressor. Do short them out with a screwdriver before gerfingerpoken.

Now if it turns out that the fans work and the comp is bad, you can do a little trick. Change the compressor plugs so that comp 1 is left unplugged, and plug comp2 into the comp1 supply. You'll only half half capacity on that unit until you get it repaired but it may keep you reasonably comfortable.