82 300TD:

1.) Disconnect battery. Open up your fuse box. It helps to remove all the fuses, as you'll be taking out the whole box. Helps to have a magnetic screwdriver too. I think the entire assembly is held in by a couple screws - but I can't remember exactly.

2.) It will take quite a bit of wiggling, but eventually you'll get the fuse box out and underneath it you'll see a bunch of wires. The wire that you will cut is on slot #11, it is grey, with yellow and green stripes. Cut this wire, strip the end, and crimp on a ring terminal. Wrap it up tightly with electrical tape or use some heat shrink tube.

3.) Connect this wire to slot #3, which I beleive supplies power to one of the parking lights. Swap the 16 amp fuse from slot #11 with the 8 amp fuse from slot #3.