Could it be another problem other than the voltage problem described on your site. Is there a relay switch not working? If it is the voltage regulator, can they have a power serge and than work ok? I noticed the check engine light on for about a minute than it went off and has not come on since. I live in a remote area with rough roads, could continual driving on a rough cause the voltage regulator to mess up or cause a wire to come loose that may be creating the problem ? Do you have a chart for tracing the headlight wiring system? Thanks Amy