Washer motor control unit, "part number replaces"

[Rob G]

I have a Frigidaire Gallery front load washing machine, model GLTF1040AS0, that is not agitating or spinning, the motor never turns, although it fills and drains and runs through the cycle otherwise. I'm shopping for a replacement motor control unit (I already replaced the door lock/switch) and on appliance repair sites when I search for the part number of my motor control unit, included in the result are a bunch of other part numbers that say "replaces part number", as in my part number replaced those. Does this mean all of these part numbers are interchangeable? Thank you.

 

[_teliaz]

Hello! Your interpretation of the part numbers is correct. When a parts supplier shows a new number that "replaces" a list of older numbers, it means the new part is the current manufacturer-approved revision. It will be backwards compatible with your machine. Manufacturers do a part number supersession when they improve a component's design or consolidate slightly different versions into a single universal replacement.

Before you order the new motor control unit, I have a question. Have you tested the motor directly with a multimeter? Checking the resistance across the motor windings will confirm if the motor itself is functional. You may also wanna inspect the wiring harness between the control board and the motor for any broken or loose connections.

On some older washer motors, the carbon brushes can wear out completely. A worn set of brushes would prevent the motor from running and would be a much cheaper fix than replacing the entire control board.

 

[superesophagus2]

Hello! Your interpretation of the part numbers is correct. When a parts supplier shows a new number that "replaces" a list of older numbers, it means the new part is the current manufacturer-approved revision. It will be backwards compatible with your machine. Manufacturers do a part number supersession when they improve a component's design or consolidate slightly different versions into a single universal replacement.

Before you order the new motor control unit, I have a question. Have you tested the motor directly with a multimeter? Checking the resistance across the motor windings will confirm if the motor itself is functional. You may also wanna inspect the wiring harness between the control board and the motor for any broken or loose connections.

On some older washer motors, the carbon brushes can wear out completely. A worn set of brushes would prevent the motor from running and would be a much cheaper fix than replacing the entire control board.

Thanks for this! Althought I need to ask, when testing the motor with a multimeter, what resistance range should I be looking for across the windings?

 

[_teliaz]

Thanks for this! Althought I need to ask, when testing the motor with a multimeter, what resistance range should I be looking for across the windings?

For the Frigidaire GLTF1040AS0, the motor windings should typically show resistance in the range of 3-6 ohms across each winding pair. If you're seeing values way outside that, like near zero or open circuit, the motor may be faulty. Check for continuity between the motor casing and each terminal to rule out shorts to ground. Did you already get a reading or are you still prepping for the test?

 

[Rob G]

Hello! Your interpretation of the part numbers is correct. When a parts supplier shows a new number that "replaces" a list of older numbers, it means the new part is the current manufacturer-approved revision. It will be backwards compatible with your machine. Manufacturers do a part number supersession when they improve a component's design or consolidate slightly different versions into a single universal replacement.

Before you order the new motor control unit, I have a question. Have you tested the motor directly with a multimeter? Checking the resistance across the motor windings will confirm if the motor itself is functional. You may also wanna inspect the wiring harness between the control board and the motor for any broken or loose connections.

On some older washer motors, the carbon brushes can wear out completely. A worn set of brushes would prevent the motor from running and would be a much cheaper fix than replacing the entire control board.

Thanks. I didn't fully understand the schematic, so wasn't sure which pins to test for which resistance on the motor, but I did try testing a bunch of pin combinations and it seemed like I was sometimes getting readings in the range of what the schematic said it should be. Also, it's a brushless induction motor.

I ended up getting one of the other part numbers for the motor control unit and that solved the problem, washer is now working as expected. The part I got had the same SW version on the label as the unit I was replacing so I figured it'd be ok to use.

I am still curious as to what actually failed on my old motor control unit. The only thing I could find to test on it was the fuse, which was not blown. I don't know much about circuit boards so didn't get any further than that.

 

[_teliaz]

Thanks. I didn't fully understand the schematic, so wasn't sure which pins to test for which resistance on the motor, but I did try testing a bunch of pin combinations and it seemed like I was sometimes getting readings in the range of what the schematic said it should be. Also, it's a brushless induction motor.

I ended up getting one of the other part numbers for the motor control unit and that solved the problem, washer is now working as expected. The part I got had the same SW version on the label as the unit I was replacing so I figured it'd be ok to use.

I am still curious as to what actually failed on my old motor control unit. The only thing I could find to test on it was the fuse, which was not blown. I don't know much about circuit boards so didn't get any further than that.

Great to hear you got the washer working again, and thanks for sharing how you fixed it. Knowing the motor is brushless clears up why my earlier suggestion about brushes didn't fit. As for the old board, it's rarely the fuse that fails. Usually, it's a power relay or another part in the power circuit, like a capacitor or triac. These parts deal with a lot of heat and electrical load over time and can fail even if the main fuse is fine. Replacing the whole unit was definitely the right call.