Goodman Furnace: Blower motor over or under voltage, or over temperature on power module
Blower motor over or under voltage, or over temperature on power module on a Goodman furnace: I see this one on jobs where the power to the house is flaky or the furnace sits in a hot spot. The motor shuts itself down when line voltage is too high or too low, or when the power module overheats. Check what the furnace is actually getting before blaming the motor.
Applies to: 34.5 in chassis gas furnaces
Common causes of blower motor over or under voltage, or over temperature on power module
- High AC line voltage to the furnace
- Low AC line voltage to the furnace, often from a loose supply connection or a weak circuit
- High ambient temperatures around the furnace
How to fix blower motor over or under voltage, or over temperature on power module: step by step
- Check power to the furnace and verify line voltage is within the range on the furnace rating plate.
- Check voltage while the blower is trying to run. Low voltage that only shows under load points to a bad connection.
- Check the installation location requirements for ambient temperature.
- Turn power off before repair.
- Replace the motor with the correct replacement part if needed.
- Have a licensed electrician check the supply circuit if the voltage is out of range.
If the unit shows an error code, look it up: Goodman Furnace codes
Source: Goodman GMVC96 Service and Troubleshooting, p. 63. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.