Goodman Furnace: Check ECM low voltage control circuit
Check ECM low voltage control circuit on a Goodman furnace: Low voltage side of the ECM. Checks the DC control signal between the control board and the motor.
Applies to: ECM blower motors on ACVC96/AMVC96/GCVC96/GMVC96
Common causes of check ecm low voltage control circuit
- No control signal from the board to the motor
- Loose or damaged 4-wire motor control harness
How to fix check ecm low voltage control circuit: step by step
- Power on, motor harness connected.
- Meter set to DC volts, because this signal is DC and AC will read wrong.
- Measure between pins 1 and 4 on the 4-wire motor control harness. It should be 3 to 15 VDC.
- No voltage? Go to the control board check, see section S-313.
- If the board is putting out the signal and the motor stays off, move on to the motor itself.
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.
If the unit shows an error code, look it up: Goodman Furnace codes
Source: Goodman GMVC96 service and troubleshooting manual, p. 46. 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.