I have the red hoover, and my motor stopped working earlier this year; i put the vacuum aside until i could get a good look at it, today was that day!
I checked continuity of all wiring and found it all to be fine, i removed the connections from the motor from the switch and it was fine too.
I then looked at the motor. It spins freely enough but my tester said it was an open circuit; thats where the trouble was. I undid the screw for the motor brushes and removed the brushes one at a time, putting each back on when i'd finished.
To get the brushes out, you have to undo the screw on the plastic brush holder, it holds it tight to the body of the motor, undo it, put it somewhere safe and to remove the brush body, you need to look first under it to see the electrical connection tab; this tab must relocate in the contact on the body when you put the brush and brush holder back onto the motor body.
To remove the brush holder you have to sit the motor so that the brush holders are uppermost, and once unscrewed, you pull the plastic part UP and back, this releases the connector tab from the body of the motor.
When you put the brushes back onto the motor you need to take care to make sure the tab connector is correctly in the plastic receiver on the motor body; push the motor in and down. Make sure the screw can line up and put it in.
Why am i talking about motor brushes? BECAUSE thats where the trouble lay! My brushes had some crud on them that had stuck to the side of the brush channel and this stopped the brush from being able to keep contact with the motor; simply, it was jammed. Once i'd freed it i carefully wire brushed the crud material away (use a small wire brush not a dirty big thing).
Once i could see the brushes were able to travel back and forth in the channels i put them back on the motor.
I could have added a very small amount of copper grease to the brush sides but in time this will dry and form a crust like the one i had just removed. Just make sure that the brushes can slide in and out in the channel freely.
I set up all the contacts and plugged the hoover into the mains and it works perfectly! Bob's yer Teapot!
Mark Hesselgreaves., July 2016