On Mar 1, 8:33 am, "visionset" wrote:
"Sam Farrell" wrote in message

...

Sounds like an open circuit armature winding, you need a Mulitmeter
across it and turn it slowly by hand checking there is continuity reading
between the brushes for each segment of the commutator.

Thanks Sam,
I attached my mulit meter ;-) to both brush holders and turned motor
(armature) very slowly.
Readings were between 1.5 and 4.5ohms - no open circuits.

Clip an analogue multimeter to the brush holders and measure the
voltage when it's running, taking due care to not electrocute
yourself.
I doubt that a digital meter will show a fast variation like that.
If the voltage goes up and down then the problem must be in the wiring
to the brush holders.
Check that the armature isn't sliding backwards and forwards.