I have a 1983 Porsche 944. My blinker fuse #8 and my hazard fuse #6 blow as soon as either switch is closed. An interesting note: with no key in the car; If the blinker switch is to the left or right the blinker lights will stay on and they turn off when blinker switch is in the off position. Any ideas on were to start to find the short?

 

Not sure about the fuses, but the blinker lights staying on with the key off is a European parking light feature. If you park along a road where other drivers may not see your car you can light upeither the right or left side of the car (depending on what country you're in) as a safety feature.

 

There is a wire in the steering column that eventually rubs and shorts out which will give the symptoms you are having. I would disassemble the column, and repair and replace any wires as needed.