Comments by "George Reynolds" (@karhukivi) on "Old car headlights were all the same — which was a fairly bright idea" video.

My old Nissan had headlamps that were getting dimmer and risked failing the annual inspection. One night I noticed that they were brighter than usual, very bright indeed and I was wondering if it wasn't my eyes. Next day I checked the generator voltage - it was 20V instead of 14.4V - the regulator had failed. Luckily I hadn't switched on the radio as that voltage would have destroyed it. So, a voltage regulator and new headlamps were required.
1