1990 Chevy Cavalier turn signals and horn

Electrical problem
1990 Chevy Cavalier 4 cyl Front Wheel Drive Automatic

The fuse to my turn signals keeps shorting out. I have replaced the fuse and traced the wires and found no splices or damage to the wires. When I replace the fuse I turn the key on and the signals work, I then start the car and the turn signals continue to work, I then turn all electrical components on i.E ( windshield wipers, radio, lights, a.C) and the turn signals continue to work. I then turn the car off and back on and the signals still work. The fuse doesn't short out until I start driving the vehicle. Please help. I am also unable to get my horn to work. I have conected the wire at the steering wheel but does not work.