Blower Motor Switch Replacement Cost Estimate

A blower motor that does not respond properly to the HVAC blower motor switch requires the testing of the entire circuit, and will likely result in a diagnosis of the HVAC blower motor resistor. However, the HVAC blower motor switch does fail, as well as the HVAC control unit microprocessor. Due to the history of blower motor resistor failures, the blower motor resistor will be inspected for visible clues first. If the resistor appears to be in good working condition, the HVAC blower motor switch and HVAC control unit will be tested first as an assembly by changing the setting of the HVAC blower motor switch and testing for a resulting change at the connector for the HVAC blower motor resistor. If the readings are inconsistent with the position of the switch, the switch will be tested, as it may not be sending the proper signal to the HVAC control unit. After finding that the changing the position of the switch is not sending the proper signal to the control unit, it will be understood that the problem exists in the switch, given that the switch has power. This bottom-up diagnostic approach may take longer in this scenario, but it is necessary because the resistor is the most likely component to fail in lieu of obvious damage to the HVAC blower motor switch.

Disassembly will have already been accomplished during testing, so the only procedure needed is to un install the switch from the HVAC control unit, and install the new switch. On some models, this may require replacement of the entire HVAC control unit, or the switch may disconnect by a solitary electrical connector. Once the HVAC control unit of HVAC blower motor switch is replaced, the control unit can be remounted in the instrument panel, and any trim can be replaced.

RepairPal recommends testing of components prior to replacement. Especially in the case of the HVAC blower motor switch where there are multiple components that will cause the same issue, testing can prevent frustration and unnecessary costs.

Failure of the HVAC blower motor switch will cause the exact same symptoms of a failed microcontroller (the HVAC control unit), or the blower motor resistor. Diagnosing these three components will be necessary to locate the true problem, and avoid replacing unnecessary parts.

Diagnosing the switch should be done by the DIYer with adequate experience with electrical and computerized electrical systems. At the very least, a basic understanding of electrical circuit testing is required. Replacing the switch can be done by nearly anyone so long as care is taken not to damage interior trim and other components during removal and installation.