How to test the generation side of the DynaStarter

[AustHaflinger]

As I mentioned in another thread I only had 11 volts in the system - car started and ran OK - the lights were just a bit dim. However the car has been sitting for 4 months and the battery is a bit old. Charged it up overnight with a smart charger but it never went into float mode so the battery is not the healthiest - however being off charge for a couple of hours the battery is holding 12.55v so according to the attached pic is holding about 95% which is pretty good.

Battery state of charge.gif (19.44 KiB) Viewed 10926 times

So the battery is OK so I thought I would test the voltage with car running - at 2300rpm and charging light out I still get 12.55v where I would expect about 13.5v - so maybe the generator is not charging at full capacity or the regulator is not working right.

Now my understanding that as the generator is exactly that a DC generator it does not need excitement like an AC generator (alternator) does. So to measure the Dynastarter system output I thought when the car was running I could pull off the +ive lead from the battery and just measure the voltage being delivered to the battery but when I did this the engine stopped just like an engine with a alternator would.

Hmm so how do I test the dynastarter output and then further down the charging line with the regulator included.

Oh and a PS - how do you tighten the drive belts - just washed my engine and will have to wait for everything to dry as the wet belts just slip on the crank pulley - know of this for a while. I will get new belts this week but how do i tension then all up?

Thanks

Garry

[tgh]

It seems the dynastarter is a dc generator, but it's the same test procedure as a rectified alternator.
Both present somewhere between 13 and 14.4v to the battery and the battery accepts what it can (measured in amperes)
So you can just put a multimeter across the battery terminals with the engine running to see if the circuit is ok.
As I recall ,a DC generator is rpm sensitive for output , so test the circuit with the engine running at say 1500>2000rpm.
After that , if you only have residual battery voltage with the engine running.. check the easy stuff first .. terminals or loose wires.
Then you need to have the regulator checked and if that's ok , then pull the dynastarter apart ( or take it to a sparky)
I have no idea what it looks like inside but old stuff typically has break downs in the windings … = $$$$$

..and that's my first contribution to this list .. please be gentle with me if I am not technically precise or you disagree with my premises…

[heinkeljb]

Hi Gary,

Did you try just measuring the voltage, with everything connected up, at the dynastart connections? I.E. Right on the dynastart body? It is possible that you just have a high resistance joint somewhere. I would at this point take the Dynastart off and check the brushes to see if they are still good. I know you say the light goes out but that only needs the voltage on both sides of it (Dynastart output and battery voltage to be the same) - does not check available current. So one brush on Dynastart will allow it to sort of work but not correctly.

As for tension on dynastart belts:-

In the fan there is a hole. Put a suitable rod in there - Locks the dynastart from turning.
Undo the nut (23mm?) on the Dynastart shaft.
Take nut off and keep any shims that are under it.
Wiggle the outer half of the v-belt pulley off.
Note the number and keep the shims you find there.
Wiggle the next part of the double pulley off and note the number of shims you find there.

Now you make the belt tighter on the pulleys by reducing the gap between then i.e. remove a shim or two!

Make sure you put the same number between each part of the pulley - too tight and you run the risk of damaging the bearings in the dynastart - too loose and it won't turn the engine over.

When you have put the relevant number of shims in place any left over go under the nut when you put that back on so they are available for het next time. You should have 6 shims as yours is a later Haf.

With your bigger engine capacity and probably higher compression - the belt will probably have to be tighter than an original engine. I have noticed that with this new engine.

Post back if you still have issues with the dynastart and we can delve deeper into it!

John

[AustHaflinger]

It seems the dynastarter is a dc generator, but it's the same test procedure as a rectified alternator.
Both present somewhere between 13 and 14.4v to the battery and the battery accepts what it can (measured in amperes)
So you can just put a multimeter across the battery terminals with the engine running to see if the circuit is ok.

Hi Mal - that was what I was expecting - I was looking to see around 13 to 14 v at the revs I was at but only had around 12.5v - the same as the battery itself so was a bit suspicious that the generating system was not up to par.

Cheers

garry

[AustHaflinger]

Hi Gary,

Did you try just measuring the voltage, with everything connected up, at the dynastart connections? I.E. Right on the dynastart body? It is possible that you just have a high resistance joint somewhere. I would at this point take the Dynastart off and check the brushes to see if they are still good.

John

Thanks John - no I did not go into testing other than at the battery so I will try the Dynastarter connections. It is a bit of white man's magic to me so I really dont want to pull it apart if I dont have too (but I said that with everything else I have pulled apart).

Re adjusting the belts - I read through your detailed instructions and my immediate response that John was winding me up - really no simple adjuster to raise or lower the dynastart - shims and all that - what a load of crock - why not a simple alternator style adjustor

As we have discussed before, we both love our vehicles but there is is so much technology in there where you ask what were they thinking - could have almost been designed by an Englishman - you know the saying "the right way, the wrong and the British way" - just kidding.

Thanks for your detailed response - great advice. Being lazy I will hold off pulling the dynastarter out for the moment as it is generating but maybe not enough and if it is an issue then do the work. I will get new belts and see how things go.

Thanks

Garry

[AustHaflinger]

I got around to do some testing today after a drive last night where system voltage was 12v no lights and 11.5v with headlights on. I have two separate voltage gauges, a dash version and one that plugs into a 12v socket I have - they are on different circuits but provide consistent voltage values. The charging light was off - mine goes off at about 1200 RPM.

Today I put the multimeter on the dynastarter when the engine was running at 2400RPM and got 14.8v At idle at about 800rpm the output was .6V

I cracked open the voltage regulator not really knowing which side is input and output so I tested both red wires which I assume one is input and one is output and both are 14.8v so this would indicate the charging system is OK - so the culprit is looking more like the battery but it does charge up however never goes into float charge on the smart charger indicating it is loosing charge a bit.

So am charging up one of my Landrover 101 starter batteries and will put that in and see what happens.

This is a pic of my voltage regulator with the cover removed, which side is input from the dynastarter and which is output to the battery and car systems?

Thanks

Garry

[heinkeljb]

Hi Gary,
Looks like you have an electronic voltage regulator on there rather than the original mechanical one.

Still the connections should be the same.

The bottom right with the 25 Amp fuse in the duse holder is the output to the car.
The bottom left is the exciter to the Dynastart
If my memory is correct, The top right should be the main power in from the Dynastart and the top left is the earth. (The first two I am sure about, the second two I will have to go and look in the workshop manual at the wiring diagram - I'll do that a bit later on to day when I have more time.

It is possible your regulator is faulty, if it is electronic, then fixing will be a bit difficult without know who made it and what the circuit diagram for it is. As a temporary measure, you could buy a VW Type 1 regulator and try that. The current settings are a bit wrong for a Haflinger but plenty of people are running them and don't seem to have problem just because of them.

John

[AustHaflinger]

Thanks John - while I have pulled apart just about everything else on my vehicle I have not had to do any thing on the electrical side so am a bit of an amateur in this area. The dynastarter even stayed on the block when the engine was in for work.

Now I didn't realise that I had a different voltage regulator to other haflingers - it is outputting 14.8v so i assume it is OK - however when it is outputting that voltage it does not seem to be getting to the battery - maybe I need to check for corroded joints in the wiring. I must admit I am surprised at how light the wiring is from the charging side of the dynastarter and then to the regulator and on to the rest of the car systems - given it can in theory carry up to 20 amps it does seem light on but my wiring is still original so must be OK.

When searching for your VW Type 1 regulator I came across the one fitted to my car - is out of a 70s VW Beetle https://www.ebay.com/itm/New-Porsche-VW ... l%3ABeetle I can get them at my VW Camper Specialist so I might get one anyway - even for a spare.

I have put in a different battery but not yet gone for a drive. I am charging up the old one but it is taking a long time so we will see if it comes up - if not maybe the battery is the issue. There are too many ifs.

cheers

Garry

[AustHaflinger]

The big starter battery that I pulled out of the haflinger has been on charge for a couple of days and after being off charge for three days is holding a consistent 12.8v which indicates it is 100% full and holding charge, so it OK.

The other battery I put in is the same so is OK as well. Yet when the Haflinger is running it is down to 11.5v so as indicated above something is going on.

Dynastarter is putting out 14.8v so that only left the voltage regulator or a dry joint between the voltage regulator and the battery that was stopping full charging power through.

So I bought a new Bosch regulator and have just put it in - straight away voltage on my instruments jumped from 12.5v to 13.8v so the issue was a dud voltage regulator.

What was confusing me was that the charging light was operating as per normal - all I can assume was that the regulator was still putting out enough voltage just above battery voltage - enough to keep the light off but not enough to charge.

Anyway all good now.

Garry

[heinkeljb]

Did you ever drive it at night? Charge bulb works by matching voltage from battery on one side against voltage from regulator on the other. If voltages are very near each other the bulb will only glow very dimly - you won't notice it is showing in daylight.

John

[AustHaflinger]

Yes - in fact most of my driving was at night and above 1200rpm the ignition light was not on at all - all I can assume is that the regulator was still pushing enough power through to match battery voltage.

[heinkeljb]

Probably able supply voltage but not current. Still glad to here all is good again with a new regulator. I would still suggest you take a look at the brushes, if only to clean away some of the carbon dust that accumulates there.

John

[AustHaflinger]

I am jinxed, so with my luck I will break something so prefer to not touch what is not broke

garry

[AustHaflinger]

So I bought a new Bosch regulator and have just put it in - straight away voltage on my instruments jumped from 12.5v to 13.8v so the issue was a dud voltage regulator.

That was on 14 November last year and I have only covered about 500km since then. I went out tonight and voltage was up around 13.8v on the way out. Coming back home voltage is back down below 12v so it looks like the "new" voltage regulator has died.

Any ideas (other than a faulty reg) on what might be killing these Bosch Electronic regulators.

Garry

[heinkeljb]

I would be inclined to point the finger at the bushes! It is of course possible that the “new” voltage regulator has gone faulty. Most times it is a bad joint on the circuit board, but the cost of a repair shop fixing it will probably be as much as a new one.
Another possibility is the windings, they do get hot and it is possible that the varnish has burnt off on a patch and that you have a short in the windings. That would produce the drop in output voltage.

John

[AustHaflinger]

Yes thanks John - the Dynastarter is a bit of white man's magic to me and I have tried to avoid touching it (lately everything I touch turns to custard - the Haflinger tune up, the air compressor on my RRS, the thermostats on my hot water system and now the electrics on the Haf).

I might have to bite the bullet and pull the dynastarter down and do a cleanup - are the bushes something I need from a haflinger parts place or are they more generic?

Garry

[heinkeljb]

I assume they are reasonably generic as when I sent my Dynastart off for a full rebuild after I mashed the end of it trying to take the fan off to do a Dynastart swap in Calais port. The place was able to put new brushes in.

The nice thing about carbon brushes is the carbon is quite soft, so in a worst case, you could source larger brushes and sit there with a knife and sandpaper and cut then down to size and shape.

Taking the Dynastart off is relatively simple compared to some of het other things you have done, so don't wind yourself up that it is difficult.

Take a photo of the electrical connections, but don't worry - they are sort of individual. The only one you need to be aware of is the exciter cable as it is a "U" type, slot under the nut as that doesn't come off.
Take the cables off.
Undo the strap on top of the fan housing. Also loosen the bolt UNDER the fan housing that holds the strap on to the crank case.
Now you can lift the whole fan housing and Dynastart from the engine.
Make note of the little pin in the crankcase and corresponding hole in the fan housing - you need to put these two together when you reassemble in order to get the timing mark in the correct place.

With the Dynastart off, you can do a quick clean if needed, then undo the covering strap at the rear of the Dynastart that covers the brushes.
Use a paint brush and compressed air - DON't forget the GOGGLES!!!!
Clean the loose carbon dust off - If you have some contact cleaner fluid, you can use that to keep the dust down.

Now you can assess the movement of the brushes, how much left you have left of them etc. The spiral spring should NOT be touching the metal brush holder because the brushes are so short the are down in the holes!

If you want to take the fan off, it is a TIGHT push fit on the shaft with a key.

Re-assembly on the engine is the reverse, but make sure you get the peg in the hole or A: the strap will be difficult to do up and B: you won't be able to do the timing properly!

Good luck.

John

[AustHaflinger]

Checked over voltages today - with engine running at 1500rpm I had 13v then it suddenly dropped to 11.5v. I put the multimeter on the dynastarter and it was at 14v so the issue is related to the regulator rather than the dynastarter.

There is a local company selling reproduction mechanical regulators that were fitted to 12v generator British cars of the 50s - these are about the same price as the Bosch electronic versions and maybe a little more robust. I might give one a go and see what happens.

Garry

[AustHaflinger]

The voltage is up sometimes and sometimes down but when it is down dynastarter is still at 14v so the issue is not there. As it is sometimes up the reg is still working sometimes - bad earth? - So I pulled it all out and put it back in - the earth is definitely working so we will see.

As a back up I have bought this mechanical voltage regulator

Voltage-Regulator-NCB100.jpg (26.16 KiB) Viewed 10180 times

This is fitted to many 50s british cars including the early Landrovers I have - the regulator is rated for 14v input and being mechanical there are no diodes and other electronics to burn out. They chatter away but will not be heard over the dakadak of the engine.

We will see what happens

Garry

[AustHaflinger]

Ok I went to put this mechanical regulator in - didn't work - mainly because it requires different wiring in the car - the Haflinger is wired like a modern vehicle that has an alternator, that is power from the battery, through the ignition switch then through the charging light and then to ground at the regulator (or an alternator) through the rectifiers that compare battery voltage against generated voltage - and light on or off.

The mechanical regulator has battery to the regulator which then sends power to the ignition switch, ignition light and then back to the same regulator terminal that takes +ive power from the generator. By sending the Hafinger switched 12v from the ignition and light to the regulator terminal that takes power from the generator I sort of got to work as far as the light was concerned but the voltmeter was not showing power being generated - hmmm clear as mud - tested voltage at the dynastarter and it is only .5v

Time to move on - so the old reg went back in and as usual 12v on start then with revs goes up to 13.4 than drops off to battery voltage of between 12 and 12.7v. Testing voltage at the dynastarter and it is only about 12.5v.

So out with the dynastarter - this is all new for me as this is the one bit I have not had any issue with.

So it is sitting on the garage floor, screwdriver in the fan hole and rattle gun set high torque undo - nothing - the big nut on the dynastarter is not moving. I am assuming it is not a left hand thread.

Open to suggestions on how to get the sucker off. John - your post a couple up seems to indicate I do not need to actually take the fan off - is that correct?

I have noted the comments on what to look for inside the dynastarter.

Any comments/suggestions are welcomed.

Garry