Bosch washing machine (WAE32464GB/01) drum not turning

[cdmackay]

Would appreciate some advice, please, with my Bosch washing machine.

It's an Exxcel 1600 Express - WAE32464GB/01

The drum won't go round, either on normal wash, or on spin.

The machine takes on water, and drains, as normal.

The filter compartment is clear, and the impellor in it turns freely.

The belt is fine, and attached.

I took out the motor; the carbon brushes were worn down to less than 1cm. I replaced with generic brushes from eSpares, and re-fitted, but it still doesn't work.

I believe it was making more noise than usual, in the week before it failed, possibly my imagination. That was last week. Has otherwise been fine, since new.

I can get a new motor from Bosch for £160, but of course I don't want to do that if it might be something else.

I would like to test the motor with a multimeter, but am not sure what pins on the connector I should be testing, i.e. what continuity/resistances should be present between which pins, etc.

Any advice on motor testing, or any other troubleshooting I can do here, please?

thanks much indeed...

 

[fidom]

It is usually possible to figure out the motor wiring just using the multimeter. First of all you can trace the 2 brush wires by removing them from the brushes and connecting your meter (on a low ohms range) between the brush wire and each motor plug contact. Next you can trace the tacho coil wires from the coil to the motor plug, probably visibly but confirming using the meter. This is the small coil on the back end of the motor and will have a resistance of tens or hundreds of ohms. The remaining contacts will include the field coil wires plus possibly a thermal overload cut-out (TOC). The TOC is often connected in series with a motor brush so if one of the brush wires shows no continuity with any of the motor plug contacts you know the TOC has failed. The resistance between the 2 brushes will be around 2 to 4 ohms and the field coil resistance will be of a similar order of magnitude. Some field coils also have a centre tapping so there may be 3 field coil wires.

 

[cdmackay]

thanks much indeed, fidom, that was really helpful

Got it working... it was the brushes after all.

Turns out that one of the new brushes wasn't making good contact with the commutator (or slip ring). This was made clear when I got the AVO on it.

That was because the brush was very tight in its channel, and not free to move, so the spring couldn't push it onto the commutator.

I freed up a little retaining clip that was restricting the brush, and once it was free to move, everything worked fine.