Alternator question

[lewy 912]

Hi Chaps,

Has anyone on here upgraded their 912's dynamo for an alternator? My 66' is struggling to cope, took it to work yesterday in daylight no problems, had the radio and wipers going, came home in the dark and by the time I got home it was dead, not even enough power to turn the indicators on. I can see it's had a new regulator recently but to be honest I think i'd rather upgrade it as I do want to use the car through the winter and need the reliability. Can you please advise which one to go for and where to get it from.

thanks a lot
Dave

[neilbardsley]

Ok firstly you should be able to run the radio, lights and wipers! Might be worth doing some checks

-> What rpm do you idle at? If below 800rpm then you aren't getting an charge when sitting at lights
-> What state is your battery in? Now it's getting a bit colder if it was already in a low charge state then you are swimming against the current. Fully charged battery hold charge for longer
-> Is your fan belt loose?
-> do you have a mechanic or electric regulator?
-> What charge are you getting from the dyno at idle and at 2k rpm with everything turned on?

As for the alternator

1) There is a one that looks almost exactly like the dyno but this is for 68/69 year size only (I believe). Have a look on Andy Prill's web site but it's probably cheaper from other sources
2) There is someone on here that sells a kits that alllows you to fit a vw alternator. Have a look for Bill thread in the 356 section

I used to keep in 67 in a garage which was 5 mins walk from my flat and I kept the battery topped up using a solar charger. I never had any issues with it not starting during the winter. Used mostly for short journeys in the dark.

[David Rooke]

Does anyone have experience of the Prill alternator - it looks super on their website, not quite OEM but much better than most aftermarket kits I have seen?

[neilbardsley]

Does anyone have experience of the Prill alternator - it looks super on their website, not quite OEM but much better than most aftermarket kits I have seen?

Sorry no experience. I believe that it's one of these

http://www.autoelectricsupplies.co.uk/product_list/141

[lewy 912]

yes I'll give the battery a decent charge tonight, it's had an electric regulator fitted at some point fairly recently I would say so there's been an issue in the past..i'll check that also..
I must admist I do like the look of the Dynalite Alternators though.. just had nothing but bad experiences with dynamos in the past..

[neilbardsley]

yes I'll give the battery a decent charge tonight, it's had an electric regulator fitted at some point fairly recently I would say so there's been an issue in the past..i'll check that also..
I must admist I do like the look of the Dynalite Alternators though.. just had nothing but bad experiences with dynamos in the past..

I didn't notice you have a 66 so unfortunately I think they are too big for you.

[lewy 912]

Right battery fully charged now, it idles at about 1200 - 1500 rpm but with the red battery light on, that stays on pretty much until I have 2000rpm... belt is tight.....

[neilbardsley]

Right battery fully charged now, it idles at about 1200 - 1500 rpm but with the red battery light on, that stays on pretty much until I have 2000rpm... belt is tight.....

It should start charging from about 800rpm onwards! I would start by checking the connections between the generator and regulator. In particular that you have a good earth. Also take off the black band and you will be able to see the brushes that touch the commutator. One on the top/bottom. They are loaded in using springs. Clean the commutator with a fibre pen (while it is moving). Then rough up the bottom of the brushes. Then try again. I recently split oil into my generator and it stopped working so I had to do this because oil had got on the commutator.



Do you know who rebuilt the generator? Maybe it's under warranty. Rob at Broadway Electronics has the equipment to the test them. He would probably only charge a small fee for a test.

PS your idle is a little too higher. You should aim for 1k rpm.

[Tclynes]

I'm in the same position with my 66, I got stuck in France with it, the Dynamo contacts were knackered and it was burning out, works now, but it's still not great and it needs replacing. Would love to know what you end up with.

[lewy 912]

Hi All,
A little more info, had the Dynamo of and checked and it appears to be 100 % perfect... for a standard 6v. My car is running 12v though (headlights / battery etc) with an electric regulator. Does anyone know where I may be able to get the dynamo 're wound' / upgraded? to a 12v?
Perhaps they offer a swap over service for mine?

any help would be appreciated.
thanks
Dave

[neilbardsley]

Yes Rob at Broadway Elec. Top chap and top service. Send him your regulator too and he will make sure it comes back working well.

http://www.broadwayelectrical.co.uk/

[lewy 912]

Cheers Neil,
just spoken to them (Rob wasn't in) they offer the service I need so looks like it's heading over there
thanks for the heads up

Dave

[Tclynes]

Dave,

I bought the alternator from AES that's linked above, I'm also running a 66 so it's not the perfect size but comes with instructions on how to get your mount machined to fit. We are doing this, though had drawn up the plan before it turned up with instructions already! I'll post a picture for you shortly.

Tom

[Tclynes]

[lewy 912]

Hi Tom,
thanks for this but have found a company locally to me called Electrostart Ltd in Daventry that can offer a re wind service on my Dynamo. I'm dropping it off with them tonight.

Cheers folks for your help
Dave