Troubleshooting Your Blower Motor When it Stays on High Setting

The blower motor has likely become stuck in the ‘on’ position at the highest setting.

Blower Motor Stays on High

A blower motor that stays on high indicates an electrical problem in the motor or a faulty blower resistor. The blower resistor is located in the engine compartment and is responsible for controlling the speed of the blower motor. In some cases, a faulty ignition switch can also cause this issue. If this occurs, it is important to turn off the vehicle, disconnect the battery and inspect the wiring for any damage or loose connection. If there is any visible damage to the wiring or connections, it should be replaced. Additionally, it is recommended to replace the blower resistor and if necessary, repair or replace the ignition switch. To ensure proper installation and operation of these parts, seek assistance from a qualified mechanic.

Blower Motor Troubleshooting

When a blower motor stays on high, it can be difficult to determine why. The first step in troubleshooting is to identify the source of the problem. This requires checking all of the system’s components and their connections.

Check Electrical Connections and Wiring

It is important to check all electrical connections and wiring when troubleshooting a blower motor that stays on high. This includes checking thermostat inputs and outputs, searching for any short circuits in wires, verifying fuse and circuit breaker statuses, and checking the function of temperature relays and capacitors. Additionally, it is important to verify voltage at relevant contacts.

Replace or Repair Parts as Necessary

After troubleshooting steps have been completed, it may be necessary to replace or repair parts in order to restore normal functioning of the blower motor. It is important to confirm that the blower motor itself is not malfunctioning before replacing or repairing other components. Additionally, it is important to identify any potential problems with the compressor unit that could be causing issues with the blower motor staying on high.

Reset Thermal Overload Protection Device if Necessary

It is important to reset the thermal overload protection device when the blower motor stays on high. This can be done by accessing the points to change the settings. It is essential to verify that all safety precautions are followed while resetting this device.

Inspect and Clean Vents, Air Filter and Fan

The vents, air filter and fan should be thoroughly inspected for any dirt or debris buildup. Cleaning the vents and the surrounding area will help ensure that the air flow is not obstructed. Additionally, it is important to inspect the fan operation and make sure it is running correctly.

Verify Condensation Drain Line

The condensation drain line should also be checked for any blockages or clogs. If there are any clogged lines present, they need to be cleared out as soon as possible to avoid any water damage. If needed, unclog the line with an appropriate tool.

Confirm High Temperature Cutout Switch is Working Appropriately

The high temperature cutout switch should be tested to make sure that it is working properly and responding appropriately when necessary. If any issues are found with this switch, it may need to be replaced in order to restore proper operation of the blower motor.

FAQ & Answers

Q: What is Blower Motor Troubleshooting?
A: Blower motor troubleshooting is the process of identifying and resolving problems associated with a blower motor in a HVAC system. It involves checking system components, wiring, electrical connections, fuses and circuit breakers, temperature relays, capacitors, and other parts to identify the source of the issue.

Q: What are some causes of a blower motor staying on high?
A: Causes of a blower motor staying on high can include wiring issues, faulty components, or a thermal protection setting being tripped.

Q: How do I check for electrical connections and wiring?
A: To check for electrical connections and wiring, you should check thermostat inputs and outputs as well as identify any potential short circuits in wires. You should also verify the fuse and circuit breaker status.

Q: What do I need to inspect and clean?
A: You should inspect and clean vents, air filter and fan as well as verify that condensation drain lines are not clogged or blocked.

Q: What is the High Temperature Cutout Switch?
A: The High Temperature Cutout Switch is designed to help protect components from overheating by automatically shutting off power when temperatures exceed certain levels. If necessary, this part can be replaced.

The blower motor staying on high can be caused by a number of issues, such as a faulty switch, a bad resistor or relay, a bad fan motor, or even an electrical issue. It is important to properly diagnose the issue before attempting any repairs. In many cases, it is best to have the repair completed by an HVAC technician who has the experience and knowledge to get the job done correctly.