Bosch Front Loader - Only Couple of Turns on Wash, Rinse or Spin Then Stops Turning

[Deep Blue]

Bosch Front Loader
WFL2480AU/04 Maxx

 

Tried searching to no avail - nothing similar posted on forum.

Motor only does 1 or 2 turns at the start of any cycle (wash, rinse or spin) and then just stops turning!

An old machine (bought new in 2000), but a good one and so reliable (like a member of the family - I'm attached to it!! )  Changed brushes twice since 2000 - that's it up until now!

Machine was noisy (like bearings on the way out) when on spin.  Checked the tub - all good, no play whatsoever.  Before I got the chance to check the motor it was washing a load and then the motor seized up - couldn't turn!

Found small pieces of metal under the motor when I removed it and the motor shaft was seized up.  Took the motor to a bearing shop and they removed and replaced the front and rear motor bearings - the rear one was shot.  Put motor (with new bearings fitted) back into the machine (brushes still about 1.5cm long).

So, water fills, water drain pump works - front panel (PCB) seems fine - solenoids click and lights go on/off as expected.  As soon as cycle starts (wash, rinse or spin) the motor starts, drum turns and then it stops.

I'm stumped as to what it could be?  Could something else have gone wrong (besides the seized motor bearing) when the motor was seized for a minute or so with power going to it?

I checked the thermal cut-out switch (Klaxon?) in the motor with my DMM and there is continuity - seems to be fine.

Is it likely to be motor (brushes, commutator, tacho, windings), PCB front panel, suppression capacitor (reduces electrical interference)?  The suppression capacitor looks fine, and there is nothing obviously wrong from a visual perspective with wiring or components anywhere that I can see.  The motor is 6 pin.

Any thoughts?  Thought of just buying a cheap replacement second-hand motor and seeing how that goes?

Just to be sure, put new brushes in, but same issue, starts turning but stops and won't continue - tried this many times - same thing on wash, rinse or spin!  Maybe the commutator is an issue? Coils? PCB? Something else?

Any suggestions?

[Whitegoodshelp (Andy)]

Hello there. If the thermal cutout switch had gone the motor would definitely not run at all it's a complete one-shot fuse that cuts power to the motor. If the motor appears to run okay for the very short time that it turns, that is it is not sparking excessively, then a common cause of the motor only turning once or twice and then stopping is either a faulty connection somewhere or a problem with the control module electronics.

I would definitely check carefully the motor plug at the end of the wiring harness that plugs into the motor. Try to pull each connector away out of the motor plug. Not too hard but firmly enough to ensure it is securely in place. Then check each of the pins in the motor itself. Gently press down on each one with something to ensure that they don't push down. Again not too hard as you will bend or break the small tabs holding them in place. But just enough to make sure that when the motor plug is plugged in one of the pins isn't getting pushed down instead of inserting inside the connector.

 

[Deep Blue]

Thanks Whitegoodshelp (Andy)!  Okay, will check those pins as you suggest.  Yes, you are right of course, if it was the thermal fuse then there would be nothing from the motor at all.  Very frustrating!  If I can't find any obvious problem, then I might just get a second motor and see how that goes!