What are the symptoms of a bad cooling fan resistor?

Another symptom of a potential problem with the cooling fan resistor is cooling fans that stay on at all times. If the resistor shorts or fails, it can cause the cooling fans to stay on even when they are not supposed to.

Where is the resistor on a blower fan?

Some common locations are near the blower fan motor, under or behind the dashboard, around the passenger footwell etc. Once the resistor is located and detached, it is often possible to say whether the resistor has burned out or not judging by the physical appearance only.

What is the function of a cooling fan resistor?

This is made possible by routing their power through the cooling fan resistor. The cooling fan resistor is an electrical resistor that limits power to the fan in steps, so that the fan can operate at different speeds according to the cooling system’s demands.

What makes a heater resistor pack go wrong?

If you look at the picture of the resistor pack the bit which goes wrong is the Transistor which sits on top of the heat sink. There are three legs which go through the PCB and are soldered on the other side (as shown). If you check the resistance between the legs you will find that a f**ked Transistor will be shorted.

When to replace AC fan speed resistor 98-04?

Buy Now! When your blower motor for the AC and heat isnt working on all settings then chances are your blower motor resistor has failed. This is usually do to moisture from the cabin air box corroding the electrical component. Here we’ll show you how to repair it and if you’re in need of a new one, check out 1AAuto.com.

Why is my blower motor resistor not working?

CLICK HERE TO RESET YOUR PASSWORD! Help! Fan quit working on all 4 speeds. AC light & recirc light still light up and AC compressor clutch engages when turning fan on in AC mode, but not getting the fan to work. I replaced the blower motor resistor and the control unit with new parts from rockauto (ACDelco).

Where is the relay on a blower motor?

Correction assuming 97 is same (probably is)… Fan relay is as posted before on top of the duct work left of the resistors you can see both behind the glove box if you take it out. The purple wire comes from the relay/resistors according to fan speed selected.

How big is the fan resistor on a Jeep Wrangler?

Replacing the resistor that helps control the fan speeds on the selector knob. If your fan only works on certain selections, its time to change this resistor. Parts at the dealership were less than $15.00 with tax, and its usually in-stock. Socket size was 5/16, 1/4″ drive ratchet. Loading…

How does resistance affect the speed of a blower fan?

The lower the resistance of the selected resistor in a pack, the higher the current that flows through the blower fan, and the faster the fan will turn.

What happens when a cooling fan resistor fails?

The cooling fan resistor is meant to send power to the fans in steps, so that the fans may operate at different speeds. If any of the individual steps or switches fail, it will disable the cooling fans from operating on that speed setting. You may notice that the cooling fans only operate at one speed, when they used to operate on two or more. 3.

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 does the resistor on a heater do?

It is responsible for controlling the blower motor’s fan speed. When fan speed is changed via the knob on the instrument cluster, the blower motor resistor changes setting, which changes the speed of the blower motor.

What to do if your heater motor resistor is failing?

If your vehicle is displaying any of the symptoms above, or you suspect that your blower motor resistor may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the component should be replaced.