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 causes a blower motor to stop working?
In a situation where the motor doesn’t work on any speed, the most likely causes are: a blown power supply fuse, a bad motor ground connection, bad motor speed control module or a failed motor. On all systems, a failed blower motor is least likely. Blower motors generally don’t fail out of the clear blue.
Why do I need a variable speed blower motor?
A variable-speed motor, on the other hand, can operate at lower or higher speeds, which results in a more even temperature throughout your home and better energy efficiency. Similar to other components in an HVAC system, the blower motor will become more vulnerable to mechanical failures as it experiences more wear and tear over time.
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.
Why does my blower not work at high speeds?
Blower works on slow speeds, but not on high speed. Check for bad fuse or bad high speed relay. Swap the high speed relay with another relay with the same part number. Also, check the fuse for the control side of the high speed relay. Make sure the ground side of the high speed relay is working. Blower works on some speeds but not others
What causes a fuse to blow on a blower motor?
If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current from a bad relay will blow the fuse and cut power in order to protect the system.
What causes a bad or failing blower motor relay?
Blown fuses. One of the first symptoms of a bad or failing AC blower motor relay is a blown AC blower motor relay circuit fuse. If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current…
What should I do if my blower motor is not working?
If it’s good, refer to a wiring diagram for your vehicle and conduct these tests: Disconnect the electrical connector at the blower motor and jumper power and ground to the motor, bypassing all the speeds controls.
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.
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.
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.
Why is my blower motor resistor not working?
If there is power indicated on high blower speed, but not low or mid range, the problem is the blower resistor. Test for ground at the blower motor if there is power indicated at all ranges, but the motor does not function.
What are the symptoms of a worn out blower motor?
One of the symptoms of a worn out blower motor is that it can intermittently produce a loud screeching noise when running. How to test a blower motor? If the blower motor doesn’t work at all, the blower motor itself must be tested first. Typically it’s done by measuring the voltage at the blower motor connector when it’s turned on.
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.