The front left turn signal has failed. Actually, this happened once
before and I changed the bulb. The problem went away. I checked the
old bulb and it was good measured 1/2 ohm like the new one. It failed
again today. I checked the bulb and holder. There was continuity
between the two metal contacts on either side of the bulb holder
through the bulb. I don't see how to check operation inside the
socket. The tail signal and the signal on the side mirror work fine.