Hi, I have a similar problem.
After 2-3 minutes, my outdoor unit to my a/c quits.
The fan blades quit moving, and there is a high pitched squeal.
I have had a professional come out on two different occasions and the starter coil, then the contacts were replaced.
My fins are clean, but it has been raining quite heavily for a while on and off. It started after we got a foot in one day.
I have tried to use wd-40 on the blades. I am not sure if I should try to try to oil the fan by trying to locate the oil ports, or if I should replace the ac unit.
My ac is over 15 years old. My thermostat does work, as it does come on at a preset time. It only lasts about 2-3 minutes before squealing, and sending in hot air.
I just changed the indoor unit filters.

 

Can you tell where the squealing noise is coming from? There are two mechanical components in the outside unit, the compressor and the condenser fan (fan on top of unit). The fan pulls air through the condenser coil (wraps around outside unit) and helps cool the compressor. If the fan stops running, the compressor will overheat and eventually shutdown. If the fan motor is squealing and then stops, the bearings/bushings are probably bad, requiring replacement of the motor. With the A/C turned off, try rotating the fan blades by hand to see if you hear or feel any resistance or noise. The motor should rotate easily and quietly.

If the fan motor has oil ports, you could try oiling it. However, do not use WD40, as it is not a lubricant. Use a light oil such as 3-in-1 or sewing machine oil.

 

Hi, thanks for your reply.
Yes, the fan blades do rotate freely when the ac is off.
At first, I thought that the blades were expanding and hitting the cowling (not sure what it's called) from heat, but I ruled that out.
It is frustrating, because it seems the pros don't know what is going on.
I'm glad the heat of the summer is finally over, so I can spend time trying to fix it.

 

I tried to oil the fan motor (I couldn't find an oil port) but it still quits after 2-3 minutes.
At least it didn't seem to squeal.

 

I have had little to no positive long lasting results in lubricating fan motors.
For the most part they are sealed and need to be replaced.

 

How do I do that?
It looks like the wires need to be done and undone, which means that I would have to figure out how to get inside it.

 

What is the make and model # on the AC? Before you decide to DIY this be aware that there is 240 Volts inside.

 

The 240 is the scary part.
It's an Interthem. I don't know the model number, but it is about 15 years old.
I see other Intertherm in the neighborhood, and they seem fine.

 

There should be a plate or sticker on the unit giving the make/model number and pertinent technical specs. If for some reason, the sticker is missing, can you read the numbers on the fan motor (assuming the fan motor is what you need to replace)? There should be an electrical disconnect near the outside unit. Be sure to disconnect the power to the unit before doing any work on it.