The passenger side blinker on my 1974 Spider activates the running light and the side contour light. (seems impossible) With headlamps on it doesn't operate at all and the passenger side running light glows dimly. The wiring shows no signs of tampering and I am at my wits end. I cleaned relevant connections with steel wool and checked for good ground. I don't have a wiring diagram yet and would appreciate a suggestion how I might obtain one. Any ideas about the mystery?