1987 Nissan Pulsar

Electrical problem
1987 Nissan Pulsar 4 cyl Two Wheel Drive Manual 130000 miles

Just 3 days ago my brakelights were working just fine. Now both of my tail lights arent working. What would cause the fuse for the brake light blow immediately after inserting a new fuse in it? I bought the #20 fuse according to the instructions, but I've gone through 4 new fuses, and only have 2 left. It instantaneously blows when I put it in. The car is completely off when I do this.

Thanks in advance for any advice.
September 1, 2010.

You have a short circuit before the fuse that powers the brake switch

Sep 2, 2010.