Boyfriend is trying to repair our window AC unit. He says the problem is the fan motor (not the compressor, etc). It'll run and cool the room for a little while (20-30 minutes maybe) and then it will die. We can wait and turn it back on, but it always dies after a little while. What exactly could be wrong with the fan motor?
will you do us a favor, and post pictures of him changing it on this site. And tell him hes gotta do it without breaking any plastic parts and cant bend any of the coils when he takes the blades off both sides of the shaft. And no swearing when he puts the clip back on the squirrell cage. Actually you can unscrew and GENTLY move both coils out of the way, but dont bend the freon lines too much, just enough to get to the blades.
The most likely cause is overheating which causes the internal overload of the motor to open. This could be because the bearings are worn and seizing or it could be because of a problem with the incoming power. If the voltage is lower than normal, the motor will draw more current (amperes) than it is designed for which creates more heat than the motor can operate with. Check the voltage source. If the voltage is okay, check to see if you have oil ports on the motor for the bearings. A few drops of machine grade oil can be applied. The bearing may be too worn, in which case the motor will need to be replaced. The motor may also have a bad start winding. Normally, a motor will not have enough torque to rotate correctly without a good start winding. It will still attempt to rotate on just the run winding, but it will draw more current and that will overheat the motor. Depends on the type of motor.
Could be bad motor bearing. Some of the older ones did have oil ports on the motor and it can be lubed up. Odds are the motor is overheating. You have to remove the unit from the window. Take off the front, and remove the case to get to the motor to lube it. You can try lubing it but the motor could be bad. And generally the motor costs most of the cost of a replacement unless it is a very large high BTU unit. Then a motor might be worth replacing but it is also a royal pain in the rear to do. Also with the case off you can clean the rear coil. Good Luck, hope the lubing will do it, if it has oil ports on the ends of the motor.
one thing that you could try is blowing compressed air through the motor to remove dirt and dust, it might help.
