Why does my blower not come on in auto mode?

Why does my blower not come on in auto mode?

It doesn’t come on if in “auto” mode but if I put it in the “on” mode, the blower comes on and I have heat. I replaced the limit switch L170-40 and still have the same problem. There is another limit switch in the blower area L140-40. I checked this one with ohm tester and it seemed OK – it was closed tester beeped.

When do you need a new blower motor?

If you are getting 120 volts to the motor and it is not starting then you have a blower motor problem and either need another new blower motor or a new blower motor run capacitor. If you are not getting voltage to the blower motor out of the control board then you probably need a new control board again.

Why does my furnace blower not come on?

I have an older Maytag furnace that will fire up but the blower motor doesn’t come on, after a minute the the limit switches will turn of the furnace because it will get to hot. I already replaced the motor, the limit switches, and the motor board but I still have the same problem.

What should I do if my blower fan wont come on?

You will need to test with a voltmeter and see if your fan motor is getting the required 110 to 125 volts AC out of your control board to start the motor. I would suggest setting your thermostat to the “Fan ON” position. You should be getting 120 volts out of the control board.

Why is the blower motor not working on my car?

My car has an automatic transmission. Hi There, The resistor is what controls the speed of the blower motor, not the relay. The blower motor relay supplies power to this motor when you turn the switch to “on” that can sometimes fail. When this happens, you may notice that you will not feel anything blowing out of the vents at all.

How does the speed of a blower motor work?

This means that the current running through the blower motor, and its’ speed is therefore controlled by the resistor value. The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack.

What are the symptoms of a bad blower motor relay?

3. Melted relay. Another more serious symptom of a problem with the blower motor relay is a burned or melted relay. Relays are exposed to high current loads and can sometimes get hot when they develop problems.

How to test an automotive blower fan motor?

Blower Fan Works on High Only 1 Locate the Resistor The location of this resistor is usually near the blower motor itself which cools the unit when it’s in operation. 2 Test the Resistor Use a grounded test light and locate the outgoing wire from the resistor to the blower motor (usually orange or red). 3 Replace the Resistor