[bluepilot]

Not exactly electronics but at least electrical. The Morris Minor had an electrical fuel pump. It contained a pair of contacts similar to the ignition contacts that old cars had. Just like the ignition contacts, the fuel pump contacts tended to weld together after a while if they weren't kept clean and filed flat. Someone I knew was having problems with the fuel pump. He wasn't the brightest and cleaning the contacts was a bit beyond him. In fact he probably hadn't realised that there were any. However he had discovered that he could get it working again if he gave it a good thump. So he rigged up a hammer under the bonnet arranged to hit the fuel pump and activated by a piece of string passed through a hole in the dashboard.