dynamo connections

[Steve Clare]

        [attachment=7424][attachment=7424][attachment=7425][attachment=7424][attachment=7424]Hello all
 I am trying to connect up my dynamo on 1927 Chummy following re-wiring and engine work....
Everything but the dynamo circuit wired nicely and functioning well.

On the end of the dynamo it has a stamped F and a stamped +.
On my switchboard it has SH (Shunt?) and D+.

Am I right in thinking + goes to D+, and F to SH ?

Also- the connections originally went to the upper left brush with the brass nuts near the F stamp, and the lower brush brass nuts near the stamped +.  Is this correct? The only reason I ask is that the + stamp is clearly on the end clamp of the dynamo, and I'm wondering if the connection should go to the screw head on the clamp.
I'm probably being dense, but the charging circuit didn't work before I re-wired, so want to check.
Pictures attached.
Many thanks
Steve

[Rick F]

Are you sure you have the correct switchboard? The wiring diagram I have (Woodrow) for a magneto-ignition chummy shows the connections as D+ and F.

The later coil-ignition CAV DEL-type dynamo is D+ and SH.

[Bob Culver]

For those without a reasonable grasp of matters electrical the Austin wiring diagrams are obtuse despite the extreme simplicity. Owners of later cars have the benefit of the Cornforth circuit diagram. For others have to draw your own. The Cornwall site article A Charging Refresher covers the charging circuit (although care necessary to associate diags with correct text) and helps especially where parts mixed.

The standard test of a dynamo is to isolate from car wiring, join F and D with an old 12v bulb from the junction to earth. As revs are modestly increased the bulb will glow very bright. Make sure wired into car as normal before running again.

[Steve Clare]

Hello Rick,
Frankly I haven't a clue. It's the type with two small holes for the inspection light at the bottom, and no ignition light.
Are there variants of that type?

[Rick F]

That is a Lucas switchboard, with "OFF", "M" and "D" on the left-hand switch. The diagram below, which is a bit confusing, shows "SH" and  "+D" on the dynamo and switchboard. I have to admit to knowing nothing about wiring mag engine chummies - mine is a 1929 coil engine - sorry