physical differences in 35A and 35M dynamos?

[JonE]

Just scrutinising Harry Hales' dynamo book - and two dynamos.

Is there actually ANY difference between an early 35A with the resistor pack - and a later dynamo?  i.e. once you have taken the external resistor pack off?

Hales' is also a bit ambiguous about the 35A resistor pack connections, stating, "looking from the top of the pack, the left connection is D and the right hand is Field".
Which way round is one looking to interpret this? (It might be easier to clarify which connection is nearer the distributor!)

thanks in anticipation...

[AustinWood]

I would assume the view is with the dynamo installed on the engine.

[John Mason]

Yes I concur with viewing when the dynamo is installed in the engine but viewing from the offside or near side.

John Mason.

[David.H]

On all mine there is  a "D" or "F" or "SH" on the bakelite(?) terminal block.  Paint and/or gunge has to be cleaned off and the moulded or impressed letter can be hard to see I am always nervous whether the right wire has come up out of the guts of the dynamo....I think  the connection to "D" is the thicker one..... unless they appear both the same gauge wire!

[Rick F]

With the dynamo installed in the car, surely the easiest way to identify the terminals is "nearest the radiator" or "front" and "nearest the oil filler" or "back"?

[JonE]

The 35A has two terminals at the dashboard end... one nearer the N/S and one nearer the O/S. I have JUST found the faintest markings on the outercover! POS ('D' I presume) is the engine side and F toward the O/S...

The only difference I've presently identified is that the attachment for the external module has two set screw attachments, rather than one for the later bakelite block.

But perhaps there are changes in the windings of this and that to give higher amperage...?

[Bob Culver]

Later 35A did not have the resistor and fuse unit on the dynamo. The output wire runs directly to the main unearthed brush so the actual presdent setup is very easily traceable, maybe with a torch and mirror. The field wire disappears delicately into the field winding. Current is much less so the wire may be thinner. If the pack is fitted the fuse should be in the field wire.

[Charles P]

Just scrutinising Harry Hales' dynamo book - and two dynamos.

Anyone know now where I can get a copy?
I know it's properly called "The Austin Seven Electrical Guide" by DG Hales but don't know of a source

c

[JonE]

Charles - I think I have you email - I'll email it to you.

[Robert Leigh]

Jon
Please will you email a copy to me as well; I have never seen one.