1971 510 wagon, L16 with auto trans. All electrical was working fine before. Going to store a few nights ago, headlights on, no issues. While driving, I honked my horn and the headlights turned off. Kinda scary but thankfully the previous owner installed cool yellow headlights mounted inside the regular lights with a seperate switch and was able to safely get back home. Checked fuses and headlights with a tester, all good. Anybody have this problem before? Looked at at wiring schematic but I might as well be reading a foreign language. Hoping for somone to say, "oh yeah, that happened to me and it was a quick easy fix. All I did was xxxxx" Thanks for any help and suggestions.