HVACopediaGoodman · Furnace troubleshooting
Check ECM control/end bell
What is going on
Checks the thermistor, capacitors and connector resistance in the control/end bell.
Likely causes
- Cracked thermistor, bulging capacitors or low resistance in the connector.
Check in this order
- Disconnect power and wait 5 minutes for capacitors to discharge.
- Disconnect the motor control and motor power harnesses, then remove the blower assembly.
- Remove the 3 screws and separate the control/end bell from the motor. Disconnect the 3-circuit harness.
- Inspect the NTC thermistor. Replace the control/end bell if it is cracked or broken.
- Inspect the large capacitors. Replace the control/end bell if any are bulging or swollen.
- Measure resistance between each terminal in the 3-circuit connector. 100 kΩ or greater is good. Replace if lower.
- Reassemble in reverse and reinstall the blower assembly.
Applies to: ECM blower motors on ACVC96/AMVC96/GCVC96/GMVC96
More furnace guides
- Airflow lower than demanded, furnace runs on low stage when high stage is expected
- Alternate combustion air opening (upflow or horizontal)
- Alternate vent/flue location (upflow or horizontal left)
- Annual inspection checklist
- Auxiliary limit control (location and purpose)
- Auxiliary limit switch open (blower compartment)
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Source: Goodman GMVC96 service and troubleshooting manual, p. 46. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.