Refurbishing a light switch
Posted: Sun Jun 28, 2026 2:02 am
Hi,
With the battery back on to iron out any electrical gremlins I found with a little persuasion everything came back to life.....
Except one.
My light switch refused to illuminate when in the sidelight position. No sides, no rears, no numberplate.
Switched to headlights, the headlights & main beam only worked. Still no sides, no rears, or numberplate.
So I bought a new one and fitted it.
Now they were permanently on!......
Faced with the possibility that I might get a replacement only to find the same problem, I chose to investigate.
The switch itself comes apart fairly easily. Unscrew the small brass retaining screw on the underside (picture 1) and the screw at the other end (nut and washers on original switches I found), (picture 8 ). On my original there is also a fibre cover plate to be eased off before I could get at that end of things.
Then withdraw the main control arm after teasing the contact ring and the insulation its mounted on off / out the other end first.
The switching control arm can be shaken out the side and into your hand and reinserted via the side slot when putting it all back together (picture 5). The one on my original switch needed a clean up.
The control ring pushes back on with the exposed section of the insulation face down, so that when in the off position the brass isn't making contact.
The hole in the middle isn't round, more oval, to aid with locating it on the arm after it's been reinserted. Once located it can be pushed firmly home.
Note the little button that holds the Bakelite knob in place needs to go back facing downwards, the same side as the flat section of the threaded part that pushes through the dash to have the retaining ring screwed over it.
The problem I found with the new unit was that, unlike the original unit where the brass part of the control ring was fitted neatly flush to its insulation mounting (picture 3), on the new one the slot it sits into on the insulation is different and it is 'crimped' in place, allowing it (if done badly) to be in permanent contact with the contact arms (picture 4). With a little recrimpimg (squashing) this was rectified, although the new switch still requires a little 'tweak' when switching up or down through lighting positions, I now have illumintion in both positions and when it is off, it now is off.
However, pulling the new one apart did have one positive aspect to it, in that I thought that, if I can disassemble the modern replacement easily enough, how hard can it be to disassemble the original and clean it up.
Hence the point of this post, as I thought I'd share how easy it is with everyone on here (who hasn't done this already).
The pictures show the components after the attentions of wire wool, wire brush and screwdriver, removing decades of grime and grot.
I am hoping that I have now restored the original to working condition, though I have yet to test it.
Please note that the names I've used for the parts are my own descriptive terms, if they have 'official' names I'm not aware of them.
Here's hoping this will be of some use to someone.
Best wishes,
Mike.
With the battery back on to iron out any electrical gremlins I found with a little persuasion everything came back to life.....
Except one.
My light switch refused to illuminate when in the sidelight position. No sides, no rears, no numberplate.
Switched to headlights, the headlights & main beam only worked. Still no sides, no rears, or numberplate.
So I bought a new one and fitted it.
Now they were permanently on!......
Faced with the possibility that I might get a replacement only to find the same problem, I chose to investigate.
The switch itself comes apart fairly easily. Unscrew the small brass retaining screw on the underside (picture 1) and the screw at the other end (nut and washers on original switches I found), (picture 8 ). On my original there is also a fibre cover plate to be eased off before I could get at that end of things.
Then withdraw the main control arm after teasing the contact ring and the insulation its mounted on off / out the other end first.
The switching control arm can be shaken out the side and into your hand and reinserted via the side slot when putting it all back together (picture 5). The one on my original switch needed a clean up.
The control ring pushes back on with the exposed section of the insulation face down, so that when in the off position the brass isn't making contact.
The hole in the middle isn't round, more oval, to aid with locating it on the arm after it's been reinserted. Once located it can be pushed firmly home.
Note the little button that holds the Bakelite knob in place needs to go back facing downwards, the same side as the flat section of the threaded part that pushes through the dash to have the retaining ring screwed over it.
The problem I found with the new unit was that, unlike the original unit where the brass part of the control ring was fitted neatly flush to its insulation mounting (picture 3), on the new one the slot it sits into on the insulation is different and it is 'crimped' in place, allowing it (if done badly) to be in permanent contact with the contact arms (picture 4). With a little recrimpimg (squashing) this was rectified, although the new switch still requires a little 'tweak' when switching up or down through lighting positions, I now have illumintion in both positions and when it is off, it now is off.
However, pulling the new one apart did have one positive aspect to it, in that I thought that, if I can disassemble the modern replacement easily enough, how hard can it be to disassemble the original and clean it up.
Hence the point of this post, as I thought I'd share how easy it is with everyone on here (who hasn't done this already).
The pictures show the components after the attentions of wire wool, wire brush and screwdriver, removing decades of grime and grot.
I am hoping that I have now restored the original to working condition, though I have yet to test it.
Please note that the names I've used for the parts are my own descriptive terms, if they have 'official' names I'm not aware of them.
Here's hoping this will be of some use to someone.
Best wishes,
Mike.