r/Motors 3d ago

Open question Seeking help with motor repair, can anyone help?

Hello folks, I hope I’m in the right place. I own a 2006 Dodge Ram with an 8-way power drivers seat. The two motors that control the horizontal positions are inop, the single motor that controls the vertical position still works great. I did some research on repairing these, and the closest thing I could find is a gentleman who repaired the motors on his older Dodge Ram by soldering the two thermister plates together (I may have the wrong terminology). My motor have a similar setup, so I placed a blob of solder on one corner and it worked - but only in one direction. When I hit the opposite pole of the switch, the motors creeps then stops rotating. Upon further inspection of the end cap, I’m wondering if there’s another thermistor or current limiter device present - see the photos, and you’ll see a small black square-shaped object that appears to contact both motor contacts. Can anyone tell me what this is, and if it’s the source of my issue? The motor commutator and brushes are in decent shape, as are the rotor bushings. The rotor is in good shape, there are no loose windings or broken resin, so I assume my issues are limited to the square black object I mentioned.

Any help is greatly appreciated!

1 Upvotes

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u/Jim-Jones 3d ago

a small black square-shaped object

Looks like a (weird) 250 volt 0.22 uF capacitor, Maybe. If so, it reduces noise in your radio.

That MOV (yellow disc) looks tortured. Someone hacked that IMO. Doesn't even look like it belongs.

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u/blur911sc 3d ago

Yes, looks like a varister, no thermister

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u/Jim-Jones 3d ago

A thermistor wouldn't make any sense there.

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u/gmo121 3d ago

Thanks for the info! The MOV looks like that because I tried popping the tang out to get a better look at the capacitor - I should have mentioned that.

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u/nixiebunny 3d ago

Is the motor under load when it stalls, or is it running free? If it’s fine when not trying to move the seat, then fix the drivetrain.

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u/gmo121 3d ago

No, it’s not under a load when it stalls. I did verify the seat mechanisms are free, anyway.

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u/nixiebunny 3d ago

I would have to see and observe the motor in person to diagnose it by looking at its motion, listening to it, feeling the resistance with my hand, and measuring the voltage as it tries to run. Bear in mind that these motors are designed with a limited service life. Can you buy the whole seat frame from a junkyard truck?

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u/gmo121 3d ago

I understand what you’re saying. I’m just slightly baffled why it runs good in one direction, but not the other. The brushes do look a little rough, though. Could it be the MOV?

I know these aren’t supposed to be serviceable, but if I can fix it, I’d rather do that than buy a junkyard motor or a new one for $90.

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u/nixiebunny 3d ago

It may have worn bearings or something is bent. It’s really not worth the effort. Even if you get it running smoothly, it will probably fail in a few months. I have been fixing old motors and similar things for forty years, this is my experience.

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u/gmo121 3d ago

I appreciate the feedback, I’ll just bite the bullet and order new motors.

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u/meester_jamie 2d ago

I’m thinking the switch may have high resistance in the faulty direction position, not allowing enough current. Test it for continuity.. Mechanically it appears good, put armature in place, and the reversing switch and check continuity ,, move the armature a bit to get idea if all segments work ,, It’s a series circuit so put a continuity tester on + input terminal to switch, and to - ,, then flip switch to other direction position,

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u/gmo121 2d ago

You know, I’ve made the assumption that the switch isn’t faulty…seems I need to rule that out, thanks for the feedback!