I have a 1978 308 GTS. It is a great car with an embarassing problem. When I turn the headlamps on, the motor runs continuously causing the headlamp to go up and down and up and down. It usually happens on one side but sometimes on both sides. I have switched out the relays and it make no difference. It would seem that there must be a limit swith that is worn out. Does anyone know how to fix this problem?