Dynamo Failure

[katy]

Methinks Ashley is confusing the points inside the distributor with the points inside the regulator box.

[bmcecosse]

Well - we all mentioned 'points in the 'Regulator box' - but I do see 'contact breaker' mentioned there - which of course has no relevance to the problem here....

[ashleywakeling]

Hi Everyone

Followed your advice and the Battery is measuring 11.88v d/c whilst stationary and whilst being revved. I'm gathering this means that the dynamo is not charging the battery? I have got an alternator kit ready to go on, is there anything else I need to do before I go ahead and do it?

Thanks!

[bmcecosse]

Certainly confirms no charge (and frankly quite a flat battery). Is the car already -ve earth? it MUST BE for an alternator....

[ashleywakeling]

I see, its starting and running perfectly every time though so the battery can't be flat! I'll put the alternator on!

Thanks again!

[bmcecosse]

At 11.88 volts it's pretty flat! If you have a charger - give it an overnight charge.

[rayofleamington]

Nothing lasts for ever, but the original dynamo / regulator box is 10 times more reliable than an alternator.
The downside is if you do a lot of stop/start traffic in winter (lights and heater on etc..) you can get a weak battery.
That's easily solved by very occasional use of a battery charger, and if you've got a driveway by the house & an extension lead you can do that without even removing the battery.

[lambrettalad]

Imagine a world cup of charging machines then the alternator would win the final against the dynamo's 2 -0 or 3-1

[taupe]

unless it wasnt playing due to injury.....

[bmcecosse]

Alternators are very reliable - as are dynamos WHEN NEW. But most are now 40/50 years old now..as are the controlling Regulator boxes.. If you have a good working dynamo system, be happy and keep using it. But if/when it packs in - get an alternator. In fact -start looking for one now ! I used to buy them for a Fiver.....not these days sadly...

[stag36587]

Sorry to piggyback on this thread but I think my dynamo has failed too - ignition light remaining on. I took dynamo off the car but for love nor money I can't undo the long screws - have tried 3-in-1 oil at both ends. After eventually managing to remove the nut and washers I also can't get the pulley off - I'm assuming that's to do with the shaft key? What else do I need to do to get the pulley off? Also noticed that the fan is spinning loosely on the shaft.

Thanks for any suggestions

[bmcecosse]

Why are you taking the screws out? And why releasing the pulley? Have you tested the dynamo? Join both terminals with a length of cable. Earth the body to the battery negative and then touch the cable to the battery positive. If the dynamo is good it will run as a motor. If not - expose the brushes (usually a cover held with a pinch screw/nut - and have a look - are the worn down or 'stuck' in the holders? Some later dynamos have no cover and I accept then you will have to loosen the screws - give them a sharp TAP to loosen the stuck threads. Leave the pulley alone.....

[stag36587]

It is a later dynamo and yes tried sharp taps on the screws. I also tested the dynamo on the car. Reason for taking the pulley off is that if (as looks likely) I need to buy a new dynamo it would be good to keep the pulley and fan - after all I am a sentimental old fool as well as Glaswegian - so don't want to spend more pennies than necessary on new parts

[bmcecosse]

Ok - so you will just need to 'tap' the screws harder! If you need to remove the pulley - try pouring boiling water over it - and then levering carefully as close to the hub as possible.

[ashleywakeling]

Just as a way to end my part of the thread, but feel free to piggback, it's what it's here for!

Alternator fitted and running PERFICK, problem solved. I've got a new one now, which I'll start a new thread for!

I hate the initial period after you've bought a car that's been off the road for a bit, EVERYTHING goes wrong!

[rayofleamington]

I hate the initial period after you've bought a car that's been off the road for a bit, EVERYTHING goes wrong!

Don't call it running in or commissioning, call it a "shake-down" period..
rather like you get after a big rebuild, things will happen.

The advantage of the shake-down term, is that when it's like being fleeced by con-men, then the same term applies!