15-10-2020, 07:22 PM
(This post was last modified: 15-10-2020, 07:34 PM by Stuart Giles.)
(15-10-2020, 02:48 PM)David.H Wrote: My real question is whether with the ignition ON should a voltage go to "energise" the dynamo? (D+ to D) I am not getting any voltage to the dynamo D nor the cut out D, so I think the most likely culprit is that the switch panel is playing up and that maybe I have disturbed the wire between D+ and IGN on the switch panel.
You shouldn't be seeing any voltage at the D terminal with the dynamo connected. The only voltage headed towards the dynamo from D+ is that coming via the ignition warning lamp. it lights through the dynamo to the chassis earth. if you disconnect the wire from the dynamo D terminal and touch it to the chassis, the warning lamp should light if the ignition is turned on. 'A' from the switch panel should have battery voltage on it, but that connection only goes as far as the cutout until the relay inside operates.
Have you tried repolarising the dynamo? it's not unknown for the polarisation to disappear or even reverse if there is some play in the dynamo bearings. Polarise the dynamo by taking a wire directly from the battery live (positive on early cars) and touch it to the dynamo F connection, you'll see a small spark and the dynamo will be polarised.
Just to add to the above, do you have a half charge resistor somewhere in the circuit? as well as continuity as in my previous post you should see continuity from the dynamo field connection to S and when you either put the ignition switch to winter full or switch the lights to 'H' there should be continuity between The D wire and the field as the roller(s) in the switch panel should short the two connections together.