Strange Square Hole.....

[Mr Jones]

I'm busy restoring a 1948 M33 which has an MU142 headlight.

It was already in bits when I got it but there's a strange square hole just to the right of the ammeter. It looks to be very precise but doesn't mean it was factory done. Being square it would suggest some sort of rotational switch. I've trawled the internet but no MU142 images show anything mounted in this position. Anybody with any ideas what it could be for?

[Rog1]

Vehicle Wiring Products sell a splash proof rocker switch that fits into a rectangular hole that's 13 x 19mm. Looking at their other switches there doesn't seem to be much standardisation in the size of the cut out they fit into, so it may be something similar of a different make, if your hole isn't that size.

https://www.vehiclewiringproducts.co.uk/c-59-switches/c-168-rocker-switches/p-706-splash-proof-rocker-switch

[DAVE BRADY]

'morning,

Is this the size of hole for B40/C15 type switches?  Why I do not know but perhaps the proper switch was defective.

Dave.

[Mr Jones]

I've measured the hole as 1/2" x 1/2".

Dave, not sure of the B40 switch hole but you are possibly correct on that. The original switch was missing parts and unusable.