Good news Dave and it's satisfied my curiosity. By rotating the cylinder where the magnets are the polarity has been changed.
In your first posting on this subject you stated that the aerial had been isolated. That's the reason. I wonder if it had been assembled incorrectly at one time. It's a permanent magnet motor more than likely and I think they have to be reassembled in the same original orientation.
The round wiper motor on later B's is a permanent magnet one and the yoke (cylinder) has alignment marks with the gearbox and has to be refitted with the marks aligned. It's nothing to do with the gearing but getting the correct polarity.
Motor polarity
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- Posts: 789
- Joined: Wed Dec 21, 2016 6:07 pm
- Forename: Vic
- Surname: Butler
- MGCC Member: Yes
- MGOC Member: Yes
- Location: North West Hampshire
Re: Motor polarity
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
Re: Motor polarity
Thanks Vic and Dave, good that we got that one sorted out!!!!
For all of us casual bystanders could we have a simple explanation of how this works please? A simple circuit diagram would be very illuminating😁
I still can't see how it reverses itself........
Ian F
For all of us casual bystanders could we have a simple explanation of how this works please? A simple circuit diagram would be very illuminating😁
I still can't see how it reverses itself........
Ian F
MGCC member
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
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- Posts: 789
- Joined: Wed Dec 21, 2016 6:07 pm
- Forename: Vic
- Surname: Butler
- MGCC Member: Yes
- MGOC Member: Yes
- Location: North West Hampshire
Re: Motor polarity
Ian, I've forgotten basic physics so I don't know why but I'll find out if I can. It's obviously something to do with the orientation of the permanent magnets. That's my theory. Doubtless physics lessons in the late 1950's early 1960's would have covered it but I can't remember. All I know is permanent magnet electric motors have to reassembled correctly hence the alignment marks on the wiper motor.
1977 Stage 2 MGB GT
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
1975 SWB Series 3 Land Rover with a later 2.5 petrol engine
Re: Motor polarity
Thanks Vic. No need to spend any more time on it (enough spent already!!) but if anyone has a simple explanation already prepared I would appreciate the enlightenment. Car electrics are certainly still a bit of a mystery to me......
Ian
Ian
MGCC member
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear