OK, car is a 1980 242, with the single round headlights. Left low beam was not owrking. Simple solution, new bulb, right ? Wrong. New bulb doesn;t work either. neither did nay of 3 other new bulbs. High beams work on both sides. Checked voltage to headlight relay, and all was normal. Checked voltage at connector to bulb, and there is 12 volts at teh connector for teh low beams on both sides, but the bulb won;t light. Checked voltage between the conector for low beams and the connector ground, and there is a good 12 volts there. Seems like there should be light, sicne we got 12 volts going in adn on to a good ground, but the bulb won't work. Please help and let there be light ! About the only thing I didn't check is the bulb failure sensor circuit, but since there is 12 volts at the socket this didin;t seem necessary.

Mike