Saab one headlight won't turn off when I turn if the ignition the light remains on. Only the driver side head light

You can set your light switch to a position BETWEEN the standard settings, that is, halfway between the normal settings. This kills all lights except when you step on the brake (which turns headlights and brakelights on anyway). I usually keep mine set between the leftmost and next settings except when driving at night. Works ok for most driving and still lights up your headlights anytime you step on the brakes, like at intersections. Headlights go off as soon as you take you foot off the brakes. This setting also saves the battery power when starting or cranking up (if you have the emergency brake on instead of stepping on the brakes). I should mention this works for me on a manual 5-speed saab. If you have an automatic, you can just ignore the battery-saver info.

Some cars leave a light on if you switch off with the indicator/turn light left on. Put the stalk to the "OFF" position and see if it goes out.