Howdy!
I also had my fair share of british electrical engineering... :wink: as my temp light also started to flicker. Certainly a case of bad grounding. I was about to perform the fix and make a better ground, but felt too lazy. It didn't flicker before, so what's changed from "then" to "now"? Bikes live in a harsh environment, and electrical connections and stuff tend to corrode. I went under the saddle, and cleaned up the battery ground terminal with a brush and some serious contact cleaner, put things back, then tightened the screw really well. Done! No problems. The light stays off.
Obviously, facts remain; the grounding is a weak point, and from the very beginning a little close to the edge. I guess it's a good thing to make that fix anyway, but not now. I want to spend every minute possible riding, not tinkering. I'll save that for next looong dark cold and miserable winter...
My oil-lamp went on too the other day. Scary at first, but it turned out to be the same basic problem; a corroded connector. Is she trying to tell me something? Like "get me a garage, you lazy s.o.b!"