Table of Contents
How do I know if my furnace blower motor is bad?
Signs of an Overheating Blower Motor A “hot” or burning smell from vents in the home. This symptom is often coupled with the furnace shutting off completely. Loud humming and other unusual noises. We have many homeowners call us mentioning humming and other odd sounds. Furnace cycles off and refuses to restart.
How do you test a blower motor with a multimeter?
Using a multimeter set on the Ohm scale, use the positive lead and test the black wire. To check the purple wire for current, use your ignition key and turn it to the run setting, turn the heater power to full power and set the multimeter to DC power. If your meter reads “no current” the motor is no good.
How do you diagnose a bad blower motor?
You might also hear ongoing whirring noises, or noises that change or get louder if you increase the fan speed. These are all signs of problems with the blower motor. In some cases, you may even notice smoke or smells of burning while driving, in which case you should pull over immediately.
How do you test a furnace blower motor?
How To Check your Furnace Blower Motor (7 Steps) Step 1: Turn off all power to the furnace. Step 2: Remove the Furnace Access Panels. Step 3: Use your voltage tester to ensure no electricity is flowing through the furnace. Step 4: Feel the area near the blower motor to determine if it’s hot.
What is the resistance of a blower motor?
According to the service manual, it must be around 4-5 ohms. In our case the ohmmeter shows open circuit, which means the resistor has failed. Sometimes, a blower motor resistor might fail due to problems with the blower motor itself.
How do I know if it’s my blower motor or resistor?
The most common symptom of a bad blower motor resistor is the blower motor will only work at one or two speeds. It can also cause the blower motor to stop working completely and you will notice no air coming from the vents.
Should a blower motor spin freely?
If the fan turns at all without forcing, it should spin when powered up. If the fan turns freely or not is not a definitive indication that is good or bad.
What makes a blower motor go bad?
Blower motor breakdown can be the result of anything from old age to failed bearings, high amp draw, electrical failure in the windings, dirt accumulation, and more. “The most common cause is dirt accumulation due to lack of maintenance,” said Tom Beaulieu, president of Bay Area Services Inc.
How do you check the voltage on a blower motor?
Keeping the black lead on a good ground, usually a bolt on the engine block, and the blower switch turned on, use the red lead to probe the plug that usually attaches to the blower motor. The meter should read between 9 and 11 volts or the test light will light up.
How do you test a fan motor?
How to Test Your AC Fan Motor Check the power. If you suspect the fan motor is bad, the first thing you should check is the power to the motor and the power to the air conditioning unit. Check the windings. Next, check the windings of the fan motor for an open or a short. Inspect the capacitor.
Can you lube AC fan motor?
While most current models of air conditioners have motors that don’t need to be oiled, many older units require periodic oiling to keep the fan in good condition. Oiling is recommended at the beginning of every cooling season. This is also a good time to inspect the fan blades and motor for signs of wear.
Can a furnace blower motor be repaired?
Standard blower motors operate at a single speed and cost around $450 to replace, including parts and labor, while variable-speed motors cost $600 and up. However, if your HVAC blower motor isn’t too badly damaged, the technician may be able to clean and repair it so you won’t have to incur the cost of a replacement.
How many volts should a blower motor receive?
220 volts should be measured for an air handler and 115 volts for a furnace. Next check for 24 volts between the blue and speed wire. If 24 volts exist replace the motor.
How do I know if my furnace blower capacitor is bad?
Signs & Symptoms of a Bad Capacitor on a Gas Furnace Blower Humming Sounds. The humming sounds created by the blower are indications that the capacitor has electrical problems. No Power. A bad capacitor prevents the blower from functioning completely. Erratic Motor Operation.
What type of oil does a furnace blower motor use?
Apply two or three drops of 10-weight nondetergent motor oil (not all-purpose oil) to each port. Do not overlubricate. If the blower shaft has oil ports, it, too, should be lubricated annually, following the same procedure. You’ll probably have to remove an access plate to get at the ports.
What kind of oil goes in a fan motor?
Types. The best lubricant for fans will generally be oil based lubricant or silicone based lubricant. An electric fan uses a direct drive electric motor. That is, there are no gears between the electric fans and electric fan motors.
