TheHaflinger.com

So, received the Dynastart back from the local shop, he found four breaks in the windings that he repaired. He load tested it, spun it up, checked for charging, everything checked out according to him. Unit had stator recut, same old brushes put in because there's plenty of life in them, wires repaired, but that's it.

I get it installed, hook up wiring, belts, etc....and no spin occurs.

Take off belts so there's no load, engage starter...spins up fine, charge light goes out so it's making current.

Put belts back on, try to start again....no spin.

Alrighty, must be a amperage issue, right? Crappy ground, or bad positive cable, right? Because battery is at full charge, starter solenoid checks out and gives full voltage across contacts and has full contact (I rebuilt it recently), so next step is grab some jumper cables, jump negative battery post directly to D- post, and then positive batt post and contact #30.

No spin, it tries, but no go. Belts aren't too tight, engine turns over freely. Take belts off giving no load situation, and starter spins up OK.

Belts on, giving light load...starter says "I'm on vacation, come back later".

If you see this, John, I see in the archives back in 2013 you had much the same issue - what did you find out? From your thread, I checked resistance, and it checks out OK according to your figures.

I shall sit and ponder this, and hope for illuminating responses from the oldtimer veterans of the Hafi wars.

Not sure I understand what you have done with this:-

"I get it installed, hook up wiring, belts, etc....and no spin occurs.

Take off belts so there's no load, engage starter...spins up fine, charge light goes out so it's making current.

Put belts back on, try to start again....no spin. "

If you took the belts off and it spins, charge light going out on shows that the voltage produced by the dynastart and battery are equal, therefore no current flowing in the bulb, hence not light.

I think you you will have to take the dynastart off and open the brushes cover and check that it is wired correctly. I know you say the shop tested it, but as it is a dynastart i.e. a motor and a generator in the same unit, no many "Auto" electrical place understand them any more. It is possible that they only tested it as a generator and not as a starter and therefore the coils used for starting are not connected up properly or have a bad joint which is preventing enough current from flowing.

I must admit it is a while since I had to play with my Dynastart (original taken off to be rebuilt and currently have my spare on Lurch).

I will take a look at mine and the wiring diagram and refresh my memory of how it works.

John

Thank you John, one thing that might also help me is to verify the connections to the brushes. Something is telling me that the shop connected things incorrectly, but unfortunately I don't have enough detail in my disassembly photos to verify. There is one brush connector that has three wires going to it, and I can't remember if that's correct.

I will bet that the issue is a broken connection, and some of the coils aren't working. Enough to spin without load, but not with load.

I've already gotten it off and on the bench, brush cover is off, and I've done some resistance testing.

If this doesn't work out I'll be sending it over the pond for a complete rebuild.

If you need somewhere to send it in the UK, I am happy to be the "piggy-in-the-middle". Lots of business don't really want the hassle of dealing with customs and couriers if they can help it.

There is a wiring diagram in the repair manual that deals with the voltage / current regulator and I think it also has the wiring for the Dynastart as part of that.

John

I appreciate the offer, might well take you up on it.

I'll have to dig through my manuals and look, again, at the schematics. I'm leaning towards there being another break in the windings, since the motor basically acts like a 24v starter running on 12v. My other option is to disassemble again, and rewind everything. Then dip, bake, etc and get it put back together.

I'm going to pull all contacts apart and do a continuity test on the windings, case, and armature today. We'll see what happens, I guess.

Still not working.

My final test was to run a direct positive to the case, and several good grounds. Still has the same issue of no torque. If it's helped along, it'll spin the belts but takes a bit of time to come up to speed. Starting from a dead stop with no help it still does nothing.

I'll try to see if I can stop by Jim L. with the unit and a few other pieces, maybe we can try something at his place to eliminate the final issue. I think at that point I'll be sending it off for a full rebuild, and I'll contact you directly, John. Thanks again for that offer!

Oh yes, and while we're at it - has anyone got a copy of a Bosch auto electrical component repair manual that deals with rebuilding Dynastarts? Or has anyone ever seen one? I'm thinking that something printed in the early to late '60's should have some rebuild and tech info.

I have not come across anything, but maybe a "how to" in a car magazine of the era?

John

Good idea. I'll have to look to see what titles are out there, and pursue it that way. I can think of one offhand that might well have it, Oldtimer-markt, but since it's a low quality paper sales pub with some tech articles now and then, folks have a tendency to toss them after they're done.

I'll check on some of the Swiss and German sites, maybe the French too.

If I do find something I'll upload it to the documentation section.

You sure the engine is not locked up?

absolutely positive.