How To Test Blower Motor

July 09, 2024 Post a Comment

How to test blower motor

Weak or Absent Airflow Weak airflow or total lack of it is the most obvious sign of a bad blower motor. The problem could be due to a clogged blower from accumulated dust or debris. It could also be due to leaky air ducts or a bad capacitor.

How do you test a blower motor with a multimeter?

Turn off your vehicle, set your multimeter to Ohms, and check for resistance between the blower's positive and negative terminals. You may also turn the car key to run without starting the engine, put the cooling system at full blast, and check for DC voltage. If none of these produces a reading, the blower is bad.

How do I know if I need a blower motor or a resistor?

Signs of a Bad Blower Motor Resistor Here are some common signs that your vehicle's blower motor resistor is bad: Loss of HVAC fan control (total or certain speeds) The fan only works on its highest speed setting. No air coming from vents.

How do you test a furnace blower motor?

How to Test a Furnace Blower Motor: Key Steps

Turn off the Power to the Furnace.
Take off the Furnace Access Panels. ...
Test the Continuity of the Motor Circuit. ...
Test the Thermostat. ...
Checking the Motor Windings. ...
Checking the Capacitor.

Will the blower motor work if the resistor is bad?

If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.

Is there a fuse for the blower motor?

Many vehicles have two fuses for the blower motor, one in the interior fuse block and the other under the hood. The blower motor is usually under the dashboard on the passenger side.

What voltage should a blower motor be?

A blower motor should receive between 12 and 24 volts of power in order to operate properly. If the voltage is too low, the motor will not be able to start or run properly. Too much voltage can damage the motor.

Should a blower motor have continuity?

The first step is to insure that there is continuity between the three terminals. Check black to white, black to red, and red to white. All should have continuity. Then check resistance.

How many volts should a blower motor get?

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.

Should I replace both blower motor and resistor?

We do suggest that you replace the resistor at the same time. It may not be critical, but this will keep the system more uniform. The issue may even be related to the resistor. If you know that it is not related to the issue, then you do not have to replace it.

Does a blower motor resistor have a fuse?

A fuse is often located on the resistor board. The fuse only protects the low and medium blower speeds. High speed will still work if the resistor fuse is blown.

What causes blower motor resistor failure?

In most cases, the blower fan resistor is failing either due to overheating or corrosion. If the blower fan fails, your car will not blow any forced air. However, sometimes the problem can be with the blower motor itself. This is especially apparent when you have replaced the blower fan multiple times.

How do I know if my furnace blower is working?

And just grab the motor a lot of times if it's been trying to start the motor will be super. Hot

How do you reset a furnace blower motor?

How to Find and Reset your Furnace Motor Blower

Step 1: Turn off the power to the furnace.
Step 2: Remove the blower compartment cover. ...
Step 3: Make sure the blower is completely cooled off. ...
Step 4: Locate the reset button. ...
Step 5: Press the button in (assuming that this is your issue and that the button has popped).

What tool do you use to test the load on a blower motor?

Most of us carry one of many electrical multimeters that are on the market to test electrical properties. On these meters, there is a selection for AC Amperage that allows for a wide range of testing sufficient for all sizes of residential blower motors. An electrical meter will range in cost from $60 to $500.

Can a bad blower motor cause no heat?

Problems with Your Blower Motor or Blower Motor Resistor Without it, there's no circulation of air—hot, cold, or otherwise. The blower motor resistor is the part that controls the fan speed of the blower motor. Both of these components can fail, resulting in the heating system simply not working.

Why do I have to hit my blower motor to work?

Blower motor only start working after i hit a bump. In most cases that is a sign of worn down blower motor brushes not making a good contact. In some cases the blower motor/resistor pigtail could cause erratic operation of the blower motor too.

Can a blower motor resistor be bypassed?

In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car's battery, which allows maximum current through the motor.

Where is the blower motor reset button?

It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.

What happens when a blower motor stops working?

Blower motor resistor / control module problems The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting (4 or 5) and doesn't work at low speeds. In some cars, a failed blower motor resistor can cause a heater fan to stop working completely.