How do you troubleshoot a blower motor resistor?

This can be annoying, but troubleshooting is easy. If you start at the blower motor, and check resistance in the circuit, you will find the problem in no time. Power supplied from the fuse panel passes through the switch to the blower resistor assembly.

Can a broken motor switch stop a blower?

A broken blower motor switch can also stop the blower from changing to certain speed settings. If your blower motor cannot change to certain speeds, check both the resistor and the switch on your dashboard. The most common failure points are the resistor and the motor itself.

Where is the fuse on a blower motor?

Locate the fuse for the blower motor in the owners/service manual. Test the fuse, with the ignition key on, using the 12-volt test light.

How can I tell if my blower speed switch is faulty?

Test for power at all the blower speeds by moving the blower speed switch through all positions. A faulty resistor loses power at different positions on the switch. High blower speed has direct power to the motor from the switch. If there is no power indicated on high blower speed, the problem is most likely the switch or the fuse.

What happens when you change the fuse on a blower?

If the blower works when you change the fuse, you may not be out of the woods yet. When the motor gets old and tired it will draw more current through the wires than a new motor.

What are the signs of a broken blower motor switch?

Some common signs of a broken blower motor switch are if the switch only works on certain air settings, which occurs when a contact wears out, or if the switch is stuck or often gets stuck, indicating that the switch is not working properly.

What should I do if my engine blower is not working?

With the key still in the off position, plug the relay back into the slot. Turn on the key and try the blower. Some relays may not activate until the car is running and have a built in delay so you may need to start the engine and wait a few seconds to see if your repair was successful.

Why does my Honda Civic blower not come on?

This test result tells you that the blower motor is OK and that the reason it’s not coming on is due to a possible problem with the blower motor resistor (known as the power transistor). Thankfully, you can test your Honda Civic’s blower motor resistor and thus be absolutely sure that it’s fried and behind the cause of the ‘no blower’ condition.

How to test Honda Civic blower motor resistor?

The following step-by-step tutorial will show you how to test the blower motor resistor (power transistor): Blower Motor Resistor Test (2001-2005 1.7L Honda Civic). CASE 2: The blower motor DID NOT come on when you turned the key to the On position. This test result tells you that the blower motor is fried and needs to be replaced.

Where is the fuse on a Honda blower motor?

Fuse #14 of the under-dash fuse box powers up and then feeds the number #2 terminal slot of the blower motor relay (on the under-hood fuse/relay box). Fuse #14 is a 10 amp fuse. Fuse #14 (of the under-dash fuse box) is the one that feeds battery power to the blower motor’s coil.

How to check battery power on Honda blower motor?

Unplug the blower motor from its harness connector and using your multimeter, check that terminal labeled with the number 1 (image 3 of 3 in the image viewer) has battery power when the key is in the ON position (position II).

Why is my blower motor not coming on?

With the back wire hooked up I ran a jumper directly to the battery pos and attached it the purple wire terminal on the motor. The motor did not come on. So either my motor is dead shorted or something has gummed up the brushes or they are worn out.

How do you test the power of a blower motor?

Unplug the blower motor and test for power using the 12-volt test light in the same manner as explained in Step 1. Testing at the motor itself eliminates the possibility of confusion caused by complicated electronic blower controls found in Electronic Climate Control systems.

What should I do if my Jeep Wrangler blower is not working?

Jerry – You had mentioned that if the blower fan simply didn’t work at all you should look into replacing the switch plug. I have replaced the switch and the resistor and still no fan. Both of the fuses (behind the glove box and under the hood) appear to be working. Where can I find the blower fan to test it? Newbie Jeep owner here – 2000 TJ w/2.5.

Where can I find the blower fan to test it?

Where can I find the blower fan to test it? Newbie Jeep owner here – 2000 TJ w/2.5. Got the TJ for a song, replaced engine with a rebuilt one then had the blower motor problem (high speed only and no speed) when it was all back together.

Where is the resistor pack on a 1997 Jeep Wrangler?

Knows a couple things… The ’97 TJ’s resistor pack is up above the passenger-side footwell, screwed to the HVAC plenum with two screws. Remove the kick plate to gain access to that area. I wouldn’t be surprised if you find some melted wiring leading to the resistor pack, that’s a common issue with early TJs.

What causes a blower fan to not work?

When this happens, you may notice that you will not feel anything blowing out of the vents at all. This may also cause the blower motor to work intermittently. A blower fan is connected to the negative battery terminal (also called ground) on one end and to the positive battery terminal through a blower motor resistor on the other end.

How does a high speed blower motor work?

In the highest fan speed state, the blower resistor is bypassed completely and the fan is effectively connected directly to the car’s battery, allowing maximum current to be supplied to the blower motor.

How is a blower fan connected to a battery?

A blower fan is connected to the negative battery terminal (also called ground) on one end and to the positive battery terminal through a blower motor resistor on the other end. The blower resistor is connected in series to the blower fan motor.

What are the symptoms of a failed blower motor resistor?

Blower motor resistor problems. Problems with a blower motor resistor are common in many cars. The most common symptom of a failed blower motor resistor is when the heater fan only runs at high speed and doesn’t work at low speeds.

What happens when a heater motor resistor fails?

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. 2. Blower motor does not work on certain settings

Why does heater blower motor increase in resistance?

As part of our comfort and luxury, the blower speed is one of the most adjusted settings in a car, and so the resistance of the blower motor is constantly being put under stress, which can eventually lead to motor failure; too much humidity in the atmosphere can lead to an increase in resistance.

How much does it cost to replace a blower motor resistor?

The blower motor resistor or control module replacement is not very expensive. For example, one of our colleagues had a problem with his 2011 Ford Escape: the fan only worked at the speed 4. He paid $50 to diagnose and $112 to replace the resistor at a local Ford dealership.

How do you fix a blower motor on a car?

Disconnect the electrical connector at the blower motor and jumper power and ground to the motor, bypassing all the speeds controls. Run a fused jumper from the battery to the power side of the motor and connect a temporary grounding jumper to the other motor terminal.

How to test Honda Accord blower motor resistor?

Testing Honda power transistor (blower motor control module). For example, in the 2009 Honda Accord, the service manual describes the procedure as follows: Turn the ignition to ON. Press and hold the OFF button and within 10 seconds press and release the Window Defogger button five times.

Why is my blower motor stuck on one speed?

Blower motor stuck on one speed A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed.

Why does my blower fan only work on one speed?

by Lee Sallings. The most common symptom of a faulty blower motor resistor is a blower fan that only works on one speed, usually high. This can be annoying, but troubleshooting is easy. If you start at the blower motor, and check resistance in the circuit, you will find the problem in no time.

What happens if you have a bad blower motor?

The blower motor is the component responsible for pushing air through the vents of your vehicle’s heating and air conditioning systems. Without it, the AC system will not be able to circulate any heated or cooled air.

What happens when a blower motor relay wears out?

Without it, the AC system will not be able to circulate any heated or cooled air. The blower motor relay controls the current used to power the blower motor, and is subject to the constant on and off switching. Over time, it can eventually wear out.

What does it mean when a blower motor does not turn?

Changes in voltage indicate that the resistor is working and that the switch is able to vary the speed of the blower. If there is voltage but the motor doesn’t turn, disconnect the plug and connect one of the motor’s terminals to a good ground and the other to a 12-volt fused source. The motor should spin at its highest setting.

When to pull over for a burnt blower motor?

If you ever notice smoke or a burning smell while driving, you should pull over immediately. A burned blower motor or motor wiring isn’t going to total your car, but you better be sure that’s where the smoke is coming from before continuing on the road.

Why is my blower motor on my Ranger not working?

I recently experienced a problem where the blower motor in my 1996 Ranger quit working. When working with your blower motor you have to first understand that the blower basically works in the opposite manner of most automotive electrical components. Normally you switch on a positive current to an electrical component to turn it on.

Why is my blower making a whirring noise?

As the impeller blades are plastic, it’s also pretty easy for them to snap off. You might hear this as a noise coming from directly behind the vent, perhaps a light slapping, or a sudden pop before you notice a problem with airflow. Whirring noises might also result from a bad bearing in the motor.

Locate the fuse for the blower motor in the owners/service manual. Test the fuse, with the ignition key on, using the 12-volt test light.

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