Courtesy light
 

So the courtesy lights suddenly quit operating on my 1990 300SE. I checked the fuse and it was blown so I replaced it. All lights now operate properly at the doors except for the drivers. I swapped switches with the passenger door to no avail.
I took out the switch and jumped the wires. No joy.
Short in the wire? Loose connection? I'm not sure where the feed goes from the switch. I'ts been a week and the fuse is holding fast.
Any ideas would be greatly appreciated.:)