Six Way Blues
My six-way light switch is a bit dodgy. It works, but when you move it to a new position you have to twiddle it about a bit to make a good contact. The lights flicker when you do this wiggling and there’s no way that it’s going to pass an MOT like that.
I got the switch off eBay, so I guess I could go the whole “bad feedback” route, maybe try for my money back. Then again, the guy sold it to me “as seen” and didn’t make any promises about it. After all, it does work… mostly.
So, I decided to have a look inside tonight. Here are some pictures. Can’t find any pictures on the web, so I’ve done a few in the hopes that they might help other people.
The connections - clean as a whistle and good as new. One of the wires seems to have got pretty hot in the past though. The inner, moving part of the switch (bend the tabs back with some pliers and pull to open it up). The copper triangles are the contacts, which sit on three small springs each.
The outer part of the switch assembly, which doesn’t turn. Inside is the track that the contacts above run on and the contacts to the back of the switch.
This metal spindle is the cause of my woes. The two tabs plug into the Bakelite back plate (in the previous photo) to stop the spindle spinning. The teeth on the spindle provide the six positions - a sprung ball bearing in the contact half of the switch assembly presses against the spindle and gives the clicking twisty action. One of the tabs is broken on my switch, so it works, but the spindle wobbles slightly as it turns - just enough for the contacts to part company and thus, to make the lights flicker.
The ball bearing, in the moving half of the switch assembly, which presses against the toothed spindle (above).
Grub screw, spring and ball bearing from previous photo.
The grub screw in place in the central moving part of the switch - only accessible when the back part is removed.