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How To Repair Room Air Conditioners

How To Repair a Room Air Conditioner Fan
The fan, motor, and compressor require routine maintenance to keep your air-conditioning unit running at its most efficient. The following are some simple guidelines.

What You'll Need
You'll want to have these tools on hand to repair a room air conditioner's fan:
  • Vacuum
  • Soft cloth
  • Screwdriver or Allen wrench
  • Long-blade screwdriver
  • Wrench 20-weight nondetergent motor oil
  • Volt-ohmmeter or multimeter


When a fan malfunctions, the problem is usually loose or dirty blades. If the fan won't operate or if it's noisy, cleaning and tightening will usually fix it. Here's how to repair a room air conditioner's fan:

Step 1: Open cabinet and locate fan.

Step 2: Clean away any debris with vacuum and soft cloth.

Step 3: Check fan blade on motor shaft for looseness. Blade is fastened to shaft with setscrew at hub of blade.

Tighten setscrew with screwdriver or Allen wrench. If air conditioner has round vent fan, tighten fan on motor shaft by inserting long-blade screwdriver through port in fan.

Fan is installed in its housing with bolts, and vibration can loosen these fasteners. Then tighten them with wrench.

Step 4: If fan has oil ports, apply several drops of 20-weight nondetergent motor oil (not all-purpose oil) to each port at beginning of cooling season.

Step 5: If you suspect fan motor is faulty, test it with VOM set to RX1 scale. Disconnect terminal wires from terminals, and clip probes of VOM to wires.

If meter reads between about 3 and 30 ohms, motor is functioning properly. If meter reads either zero or an extremely high number, replace motor.

To remove the fan motor, remove the fan, the power wires, and several mounting bolts. Install the new motor with the reverse procedure. However, if the condenser coil must be moved to get the fan out, do not try to remove the motor. Call a professional service person.

By following the routine maintenance mentioned in this article, you will be able to handle most problems that occur with your window air conditioning unit.

For more articles on home repair, check out the following links.
  • How To Repair Central Air Conditioners: If your system sends cool air to all parts of the house, you've got central air. Keep the system running cool.
  • Major Appliance Repair: If the a/c isn't the only thing in your house on the fritz, you can learn how to fix other machines in this article.
  • Small Appliance Repair: Once you've tackled the a/c, a toaster or blender seems like child's play. Find out how to fix them here.
  • Thermostat Maintenance: To make sure there's actually a problem with your a/c, you may want to check the thermostat, too. Learn how to calibrate a thermostat.