Goodman Furnace: Check line voltage to the furnace
Check line voltage to the furnace on a Goodman furnace: Confirm the supply voltage at the junction box and at the blower while it runs.
Applies to: Gas furnaces ACVC96/AMVC96/GCVC96/GMVC96
Common causes of check line voltage to the furnace
- No reading can mean open wiring, an open fuse, no power, or a faulty door interlock switch.
How to fix check line voltage to the furnace: step by step
- Turn power off, remove the burner door, and remove the junction box cover.
- Turn power on with the door interlock switch engaged. Measure voltage across hot and neutral with a voltmeter.
- If there is no reading, check wiring, the fuse, power supply and the door interlock switch.
- Jumper R to G on the integrated ignition control to run the blower.
- With the blower running, voltage should be 115 V within plus or minus 10%.
- If voltage is low, check line wire size. Undersized long runs can cause low voltage. If wire size is adequate, notify the power company.
- Reinstall the junction box cover and service doors, then restore power and verify operation.
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. 43. 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.