A friend of mine has a F-150 a year newer than mine (1998) and can't figure out what is going on with his blinkers. They do not work unless he has his steering wheel all the way up and holds it there. The blinkers will then work. As soon as he lowers the wheel... nothing. What is going on?

 

The connector in the steering wheel column is pulling apart.

Pull the anitsubmarine panel ( knee panel ) off, and follow the wires up into the steering wheel column ( might have to take the steering wheel column cover off, 3 screws on the bottom ).

There is a connector ( I think 24 or 34 pin, 2 rows x 12 to 17 pins wide ) that is pulling apart. Pull the connector apart, and check for blackened pins. Clean them up with contact cleaner.
When you put it together, the connector tab might be broken, and you will need to put it together with zip ties or the likes.

Pull the harness up from the dash side, and zip tie it to the bracket under the dash, so the harness does not pull tight again.

Good luck, take pictures and post them here if you can.