New fan belt, now have red light

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Apolaustic
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Re: New fan belt, now have red light

Postby Apolaustic » Mon Apr 15, 2019 7:37 pm

Jenko - I’m not going to add to the practical advice, but I echo Myoldjalopy; don’t give up! There are bound to be issues with a decades-old car which has been through several (or more) pairs of hands. And I agree, mechanically it’s all relatively straightforward to sort out; it does need a patient logical approach and you’ll need to curse and walk away to take a break from time to time. Once it’s right, you’ll know and you’ll be able to keep on top of it. Have a ☕️ or whatever your tipple of choice. 🙂.
Apolaustic
1966 white/red convertible (1098cc with alternator, electronic ignition & brake servo)

Shropshiremoggie
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Re: New fan belt, now have red light

Postby Shropshiremoggie » Mon Apr 15, 2019 8:39 pm

The car you now own is a little gem. OK a few initial problems but the advice and expertise you will find on this site is second to none , and never forget the encouragement from fellow owners !! I drive a couple of so called ‘ modern cars ‘ but my favourite is my Moggie . Parked at my local it attracts loads of people and favourable comments , a real ice breaker ! Hang on in — its worth it !!!

oliver90owner
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Re: New fan belt, now have red light

Postby oliver90owner » Mon Apr 15, 2019 8:41 pm

Still costs nothing to flash the field windings. So easy to do and if it needs doing it simply won’t be charging.

Jenko
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Re: New fan belt, now have red light

Postby Jenko » Tue Apr 16, 2019 7:24 am

Thanks MOJ
I did clean the terminals yesterday, but they all seemed fine anyway. As you said though, it's often something like that but unfortunately this time it Didn't make any positive difference.
I'll get round to doing those checks that you just described this week sometime. It's the same check as described in the workshop manual I have although you have described it better and it makes sense now.
Hopefully your check will prove that it's just the Dynamo and a simple swap for a new item will fix it for me. Nice and simple!
I'll have a shop around, but I saw that Charles Ware have one for around £60.

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Re: New fan belt, now have red light

Postby Jenko » Tue Apr 16, 2019 7:26 am

Thanks for the other positive comments!
I've tried flashing the windings, as you advised, but made no difference, unfortunately.

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Re: New fan belt, now have red light

Postby Jenko » Tue Apr 16, 2019 7:32 am

But let me just check that! I put a cable on the positive connection on the battery, which is Earth on my car. Then after disconnecting both terminals on the dynamo, just brush the other end of the cable over the smaller terminal on the dynamo. Is that right?
Just going off previous forum posts here, but it wasn't clear if it was done on a pos earth or neg earth.
Thanks

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Re: New fan belt, now have red light

Postby pgp001 » Tue Apr 16, 2019 8:06 am

Jenko

You need to disconnect the lead from the negative side of your battery, leave the positive earth connected to the chassis.
Then use a wire to connect the negative pole on the battery to the field terminal on the dynamo for a second or so.

Thats it.

Phil

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Re: New fan belt, now have red light

Postby Jenko » Tue Apr 16, 2019 3:46 pm

Sorry to sound a bit dense.
The field terminal is the F terminal? The smaller one of the two on my dynamo?
Just checking.
Thanks again.

myoldjalopy
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Re: New fan belt, now have red light

Postby myoldjalopy » Tue Apr 16, 2019 5:26 pm

Yes, the smaller of the two terminals on the dynamo is the 'F' or 'field' terminal. Flash it with a wire taken from the non-earth battery post (in your case, the negative terminal, as your car is +ive earth - just like Phil says). Remove the F and D wires from the dynamo (tape them off, to be safe) before you polarise it and be careful you don't short out the 'flash' wire anywhere else. Just flick the wire over the F terminal two or three times - you should see a little spark.

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Re: New fan belt, now have red light

Postby Jenko » Wed Apr 17, 2019 1:58 pm

myoldjalopy wrote:
Tue Apr 16, 2019 5:26 pm
Yes, the smaller of the two terminals on the dynamo is the 'F' or 'field' terminal. Flash it with a wire taken from the non-earth battery post (in your case, the negative terminal, as your car is +ive earth - just like Phil says). Remove the F and D wires from the dynamo (tape them off, to be safe) before you polarise it and be careful you don't short out the 'flash' wire anywhere else. Just flick the wire over the F terminal two or three times - you should see a little spark.
ThanksMoJ, I did this but light still stays on.
I'll go ahead and do the charging voltage check now
Watch this space!

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Re: New fan belt, now have red light

Postby Jenko » Wed Apr 17, 2019 2:15 pm

myoldjalopy wrote:
Mon Apr 15, 2019 5:25 pm
OK - the dynamo should run 'briskly' as a motor and without hesitation. And yes, I think the dynamo will run as a motor in the test I described without ignition being 'on', as you have found out.
Another dynamo test is to disconnect the F and D wires at the dynamo and tape off the ends so they can't short out anywhere and to then connect the F and D terminals of the dynamo itself together with a short piece of wire. Then connect the -ive lead of a voltmeter set at the 20v range to this wire and earth the other (+ive) lead to a good earth point. Start the engine and carefully increase the engine speed - the voltage reading should steadily increase. Try not to let the volts rise above around 18 or 19 volts or you may damage the dynamo. If you can only get a low reading (remember, the charge to a battery should be up to about 13.7/14.0 volts when the system is working properly) or none at all, I would say the dynamo is faulty and that would explain why your cut-out doesn't operate. If this test proves the dynamo sound, then I would suspect the connections at the control box, or the box itself. Do try giving those contacts a clean though, as I previously suggested, if the dynamo is proved OK.
Don't give up on the old girl yet. Often previous owners have neglected/bodged work on these cars and, at some point, this neglect will come home to roost with a new owner. But, at some point, all problems will have been rectified and then you have a reliable little car which only needs periodic servicing.
Ok, I did this check, connected the -ve lead of my voltmeter to the wire, (actually to the F spade on the dynamo after bridging the 2 terminals with a heavy piece of wire) and the +ve lead to the battery earth point. At a fast tickover I got 1.5 to 1.8 volts. As revs increased slowly, it went up to about 4.5 to 5 volts.
Nowhere near 13 volts. So I guess that I've just confirmed that the Dynamo is unserviceable.
Fleabay have new ones for £62 for a C40, which is the same as some Morris Minor specialists but free postage.
Simple job to change, so I'll get one ordered.
Hopefully that might be ok for a few trips.
At present I'm averaging 60 miles per repair!

pgp001
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Re: New fan belt, now have red light

Postby pgp001 » Wed Apr 17, 2019 3:25 pm

I would consider fitting an alternator conversion kit, they are about the same price.

Phil

Jenko
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Re: New fan belt, now have red light

Postby Jenko » Wed Apr 17, 2019 4:21 pm

pgp001 wrote:
Wed Apr 17, 2019 3:25 pm
I would consider fitting an alternator conversion kit, they are about the same price.

Phil
Thanks Phil, I did consider that but they're much more expensive. The kit is approx £90 more than the Dynamo I've ordered from Bull Motif, and I won't have to do any additional work, ie changing from pos earth. At the moment I just want to get her running and usable. She's my only car and I'd like to just enjoy her as she is, just without the breakdowns! Although to be fair, I've managed to get home every trip.
Thanks for the suggestion though, I do welcome all hints, suggestions and shared expertise.

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philthehill
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Re: New fan belt, now have red light

Postby philthehill » Wed Apr 17, 2019 8:00 pm

Jenko
I do not know where you get the additional £90 from as the Bull Motif alternator conversion kit is £74.34 inc Vat.

ESM alternator conversion kit is £69.50 plus VAT.

BullMotif C40 dynamo is £59.70 inc VAT.

ESM dynamo is £52.90 plus VAT.

Fitting the alternator conversion kit is one of the best moves you can make and is so easy to do.

One of the first conversion items on my 1098cc engine Ser 2. I never looked back.

Phil


oliver90owner
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Re: New fan belt, now have red light

Postby oliver90owner » Wed Apr 17, 2019 8:56 pm

Unless to retain the original looks, I would never replace a dead dynamo with another - unless I had one laying around.

Alternators are self contained so don’t need a separate voltage control box (another possible ‘breakdown’ item).

All the motor manufacturers have not fitted alternators, for the last 5 decades, for no good reason!

myoldjalopy
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Re: New fan belt, now have red light

Postby myoldjalopy » Wed Apr 17, 2019 11:57 pm

Well, he says he's already ordered a dynamo! I have replaced my dynamo once in the last 19 years - and the old one looked pretty ancient - and I have to say, in over 38 years of motoring and six cars I have had three alternator failures and two dynamo failures. Of course, if you want to run radios, CD players, have flashing lights etc. then an alternator is a safer bet.......

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Re: New fan belt, now have red light

Postby Jenko » Thu Apr 18, 2019 3:30 am

Oops. I’ve opened a can of worms. I misread the price. Sorry.
Anyway, I ordered the dynamo now, with a few other bits n bobs for only £75 the lot. I reckon this dynamo might be the original one, as I’ve got all the receipts from the rebuild in 2014 and there’s nothing for a dynamo.
I take your point about the alternator though. If I’d received the replies before ordering, I would’ve looked more into the alternator conversion. Hopefully I won’t have to replace it again soon but if I do, alternator is another option.
I’ll let you know what happens with the new dynamo

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Re: New fan belt, now have red light

Postby ManyMinors » Thu Apr 18, 2019 7:45 am

Don't worry. I've been perfectly happy with my dynamo equipped Morris Minor all these years. I put some new dynamo brushes in some years ago (an easy job) but apart from that I have never had an issue with it. The car starts up every morning and carries out its duties without ever a flat battery or failing to keep up with electrical requirements. I think the problems start when you replace good quality original parts with cheap, poor quality new ones and several owners have reported problems with new replacement control boxes. As Oliver says, one advantage of an alternator is that it doesn't require this secondary device but the originals are generally reliable and better replacements are available than those offered cheaply by the usual suppliers I understand.

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philthehill
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Re: New fan belt, now have red light

Postby philthehill » Thu Apr 18, 2019 7:56 am

When replacing the dynamo brushes the commutator segments must be parallel not uneven where the brushes have worn them (usually rectified in a lathe) and the commutator segments must be undercut. See BMC wksp man Fig. N5 for details.

Just replacing the bushes is only doing half the job.


oliver90owner
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Re: New fan belt, now have red light

Postby oliver90owner » Thu Apr 18, 2019 8:54 am

myoldjalopy wrote:
Wed Apr 17, 2019 11:57 pm
Well, he says he's already ordered a dynamo! I have replaced my dynamo once in the last 19 years - and the old one looked pretty ancient - and I have to say, in over 38 years of motoring and six cars I have had three alternator failures and two dynamo failures. Of course, if you want to run radios, CD players, have flashing lights etc. then an alternator is a safer bet.......
In over 50 years of motoring, I think I have only replaced one dynamo - because that was the only one I have had on a car during my 60+ years of driving, and it was not even dead at the time (changed for more electrical power).

I’ve repaired a few alternators in that time - usually a replacement voltage regulator or new brushes and slip rings and some drive-end bearings. I’ve come across lots of dynamos on old tractors and replaced, or repaired, a few. But the way forward is the AC alternator, whatever anyone else thinks.


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