Fan outside goes on and off. I am worried that something is wrong

Every airconditioner will create condensation that needs to drain. Your condensation is not going where it is supposed to, probably because the drain is plugged. Find the cooling coils (they might be in the basement, but are probably in the attic) they will be right next to the fan. There will be a pan or tray under the coils and there will be some kind of small diameter pipe or hose that should go to a sewer inlet, or might possibly go outside. You might possibly have a small collecting tank with a pump that will be operated by a float switch. Lots of possiblities, but it is likely going to be obvious once you find the drain hose.
Good luck.

Check the capacitor for the fan first.

Has it always made that noise? If so then I would think that after 4 years and no problems that it is nothing to worry about. If it is something new then turn it off and call a service tech to look at it. I am leaning toward the service tech.

Your condensor fan motor has more than likely gone out. This fan should run at all times when the unit is on. Since the fan isn't working then the motor must have gone out.

Dave

check your circuit breaker.

Sounds like it cycles on either head pressure or low pressure. If you have a Carrier unit it has both controls. Is your outside fan running. Is your condensor dirty. A unit that old needs to checked bby a service tech. Remember freon does just go away. If he puts gas in your unit there is leak. HINT Ask for free estimate on repair before it is fixed. That way you know the cost up front. Rus

no cooling means outside unit is not operating due to
-no thermostat signal
- condenser dirty need cleaning
- fan motor stucked 90% this the reason of noize

It sounds like you might have a short in the wiring that goes from the furnace (inside part) to the condenser (outside part). Follow these lines by hand and check to see the wire isn't damaged and shorting out.

You have done a good job under the circumstances. It could be a bad start/run capacitor as well. It carries a lot of amperage so I suggest hiring a technician to check the capacitor and the motor.

This unit has a bad Start/Run Capacitor or a bad Fan Motor! Replace the $10 Cap...An then the $90 fan motor if the Cap dont solve it!