Re: Electrical gremlin...
This is commonly a broken wire in the drivers door boot, the one which goes from the door to the body. The black wire is normally the one which breaks, because its a too stiff wire and due to the flexing when opening the door it will break eventually.
When yours still works now and then, it can be that the isolation is still intact. Remove the boot from one side and have a look. feel the wires and especially the black one for an internal wire breakage. The access is not that good.