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Well, power to the battery on my 1930 7-45 actually

The voltage across my battery is 6.24V

When the engine in running it varies from 6.14 on tickover to 6.08 at higher revs.

Clearly there's no charging going on.

Can anyone rescue me with a trouble shooting process for the system and/or details of the generator, regulator etc

Thanks

I would check the voltage regulator first. See if you are getting current from the armature to the regulator. If so, then it is probably the regulator.

It's a 3rd brush generator so you can start by just turning the adjustment a bit to a higher charge rate (see service letters or PM me). If that doesn't do it, and the chances are it won't, problem is no doubt the Owen-Dyneto cut-out/regulator, though it's worth a look at the generator and brushes first. You can remove the generator without dropping the timing chain - just don't remove the large bronze flange - it holds the sprocket to the chain. Your Dyneto unit is not a current regulator, but a more primitive type of voltage control and cutout. Supply of these hasn't been a problem until just recently when NAPA discontinued them - they're hard to find and even harder to find someone to repair them - you might try ACE in KS who advertises this type of service in many hobby publications.

Owen-Dyneto data on generator and control is quite plentiful. PM me if you wish.

kts68: Should have said it before, but if you intend to use this car on tours and the like, it really makes sense to remove the generator and check it out thoroughly, even though that may not be the current source of your problem.

It has a rear bearing, but the front bearing is on the timing chain so it's difficult, even here, to find a shop that can bench test the unit as it takes a special jig to support the armature. But even without a dynamic running bench test, a good check over, new brushes, turn the armature if necessary, check for shorted fields and segments, etc. will all ultimately lead to a more reliable road car.

BTW, that voltage at the battery in static condition seems a bit low, the normal voltage for a single lead/acid wet cell is about 2.2 volts, so it should be closer to 6.6 volts.

EDIT: Original equipment for 740 and 745 was Owen-Dyneto CD-865 generator and regulator 20220. Regulator relay should close at 6.5 to 7 volts, and open at a 0 - 2 amp discharge. Contact gap 0.015", core gap with contacts closed 0.010". A 6.5 volt cut-in corresponds to about 550 engine rpm, 7.0 volts to 600 rpm

What a day.....

I just spent 6 hours removing, stripping, rebuilding and refitting the generator and...... nothing !!!

I first studied this rebuild from packard paddock (really useful website)

packardpaddock.com/page2/page7/page7.html

My generator obviously has a fairly new shaft and commutator but the wiring to the bushes was in a state. When it was reassembled last time the wires were trapped and worn down and copper dust was everywhere!

I carefully cleaned and rebuilt the whole thing but there is absolutely nothing coming out. The adjustment on the 2nd (3rd?) brush makes no difference even though I thought I had found the problem as this brush was stuck and not even contacting the commutator.

The other puzzle is that the regulator is not the original - its a Bosch unit but even so there is no voltage going in to it.

I suspect that there is a clean break in the internal wiring or major problems with the field coils.

Oh well, time for a hot bath and a beer!

May have to invest in a replacement..... how much $?$?$?$?$

Perhaps a shorted segment in the armature, or break in field windings? If the generator is a fresh rebuild and has a new repro ID tag riveted to it, it wouldn't be the first time that someone used a rivet too long and it penetrated the field windings and ruined one of them.

I'd check each segment of the armature (copper segment) for a ground against the shaft. And you can also test the fields for continuity with an ohm meter or similar.

I've heard of folks using Model A generator cut-out as a temporary measure, though I have no experience there.

I'm sure you'll keep us posted as the mystery unwinds.

Thanks again for your suggestions OD.

Good point about the replacement metal badge - I notice that these are available all over the web, but no, it looks pretty original.

I had a quiet think about this and wonder whether I have connected the brushes the wrong way round. Obviously brush number 2 is hard to get wrong as it is grounded.

But if brushes 1 annd 2 are the wrong way round might that produce 0 volts? It occured to me that the generator would only produce a charge when the brushes were the wrong way round if the armature was spun in reverse. As this is not possible (driven only one way by the motor) it follows that the the phasing would always be wrong. I would appreciate your opinion on this.

I'm sure it is something as silly as this as I did rebuild it very carefully and it is now very clean.

The only other thing I could think of would be a complete break in one of the two wires out of the generator but they are thick and short.... either that or a really bad short somewhere that grounds any potential before it can be measured.

If it were a case of damage to the windings or the commutator then I would have expected a small voltage but intead there is nothing.

So I think that someting is reversed because when I checked the voltage from the generator before I stripped it, there was a small reading (0.03V) was not surprising considering the state of it inside but something nevertheless.

Its late now so I will have another go at it over the weekend.

Check battery voltage getting to either the Field post or armature post of the generator.

In general, there are TWO types of generators:
Field ground. Armature ground generators.

I don not know which type your generator is because i don;t have the books or an original to look at. If some one has modified the generator from original ground type to the other type (usualy done for regulator swaps) then that could be the problem.

The SERVICE manual should give somekind of generator test procedure BYPASSING the regulator. That test should be done BEFORE taking action on the generator. Should be done now that u have a continued problem.

SO in summary:
Possible incompatible regulator with generator grounding type.

Possible grounding (armature or filed coil) of generator has been changed or is incorrect.


First need to run the test bypassing the regulator. Note that if the service manual test indicates to ground the "F" terminal and that does not work then try the "A" terminal.


First follow the test procedure of the manual !!!!!!!

I really don't have an answer to your question, but does this help at all? Source is Standard's Auto-Electrician's Manual, 1934

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Since the generator was disassembled then it should be POLARIZED!! THis is covered in the SERVICE manual.