Hi I have a Grinnall Scorpion ( K1100 ) which has a charging problem. When the temperature is below around 10 degrees C, the charge light will not come on when the ignition is turned on.  After an hour or so in the sun,  the charge light comes on.  So, the bulb is OK.  I have a spare speedo cluster from my K1100 outfit and when that is fitted everything is OK, and the car charges correctly.  So, the problem must lie in my speedo cluster.  Before I go looking, I thought I would ask if anyone has encountered this before, which might save me a bit of time.  Could it just be a dry joint in the circuit board? Any help appreciated.

I don’t know if you have checked the printed circuit board or not. I had a light that refused to light, new bulbs did nothing, it turned out to be the tab on the pub was folded over and it only got intermittent contact.
Also check the pins on the rear of the cluster.

I've encountered loose globe holders and had to clean and tighten their tangs by gentle prying. If you have LED's fitted they are polarity sensitive, you may have to rotate the holder.
Regards Martin.

Thanks for your replies.  I've just had a go at the original instrument panel, and discovered the problem.  The little plastic bulb holder for the charge light bulb has a double contact where it connects to the copper tabs on the circuit board.  One of the tabs was missing, and the second one was almost worn away.  All the other bulb holders looked brand new, so either a second hand bulb holder has been fitted at some stage, or there is some corrosive action going on with that particular bulb holder.  Anyway, at least I now know what the problem is, and if it happens again, I'll have the solution.  There is a spare bulb holder where the early Ks had a 2nd low fuel warning.  So, I''ll always have a spare bulb and holder.

I've got a shedload of those spare. PM me if you'd like a couple more.