The problem with the originals is they use bimetal strip vibrator technology, similar to how a flasher can works but @ much higher frequency.
Over time the contacts inside get grotty and it doesn't work as originally.
Mine was interesting- the faster I drove, the lower the fuel gauge would read, then when you stopped @ the lights you could see the gauge come back up.
But if I ran it up on stands in the garage at 80 or 90 kmh or more it was fine.

It was road/body vibes upsetting it.
So, I fitted a Wombat electronic 10V special and it's been fine ever since.
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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.
