I had this same problem. As pointed out, The multi function switch was the culprit. The later model years problem was the wiring where the tilt bends was pulling the wires fron the contact enough to break the connection, or breaking the wire. ON mine I pulled it apart and made sure of all the contacts were in good order and good conections. BUT you have to use the TAMPER proof Torq bits to pull it apart. They are the ones with the hole in the center. Can get them @ Napa or Sears. Maybe other places to.
any way it solved my problem.
Marv.