On 23 Feb, 20:43, "Jim Alexander" wrote:

[...]

Google "DZ47" and you will learn something to your advantage.

I didn't. What exactly do you think I might learn that would be to my
advantage?

But to get back to your problem, I don't think the make is as important as
the system design issues alluded to by several people here but which you
don't yet seem to have acknowledged.

It's not that I haven't acknowledged it, it's just that I haven't the
faintest idea what they're talking about! Seriously, electrics is a
Black Art as far as I'm concerned. I originally posted hoping someone
would give me a few steps that I could take to locate the problem. As
the thread has gone on, it's become increasingly clear that there may
be any number of possible solutions, almost none of which I am
personally competent to pursue.

Edward