Dynamo causing flicker lights

[Pikey]

I awoke the pickup from her winter sleep today. First time shes been started since last October. She started without issue but the interior light that I had on because the door was open, was flickering/flashing with the engine revs. Im guessing it was because of the regulator was sorting out the dynamos voltage, but Ive never seen it flicker and flash before.

Is that normal for a dynamo or should I clean something like dynamo brushes or regulator points.

Shes positive earth and dynamo. But perhaps the battery was a tad flat and the dynamo was making hard work of it?
Cheers

Steve

[simmitc]

It could also be as simple as the door switch being a bit rusty through lack of use, and then the vibration from the engine running giving a poor connection. A bit of switch cleaner and rotating the plunger between thumb and forefinger could work wonders.

Ideally a battery should be charged during the winter, but if it had enough power to start the car, then a 5w interior lamp should not be a problem. Presumably the warning light went out, confirming that the dynamo is charging the battery? Try a bigger load - turn the head lamps on, and check that they glow brighter as you rev the engine. If you have a meter to hand, then that is even more reliable for testing the output.

[Andy]

This sounds normal to me. The tiny bulb in the interior light is very susceptible to fluctuations in the supply voltage. The Minor's voltage regulator is an electromechanical affair that gives, at best, an approximation of a steady supply. The flicker will probably be worse at part throttle when the regulator cut-out closes but the dynamo output is still quite low. This would be the case when running a car on choke as the revs would be slightly increased.

Nothing to worry about.

Andy