Headlights and dash panel cut off intermittently while driving on smooth pavement for past 10 years. I have had dealership experience this but they could not find any problem. Also, the speedometer shows car speed at 100 or more mph when starting car but goes to normal when moving. I just replaced the motorcraft alternator with a rebuild version and the speedometer problem is gone. Can't be sure that the headlight issue is gone too, but this seems to be the magic fix. I'm wondering if a batch of intermittently defective motorcraft alternators were oem since this seems to be a problem for others. It is very scary to be driving 55 mph and have the headlights cut off for a short time. Months go by and nothing happens; then there it is again. I was thinking that the car was haunted. I still have the old motorcraft alternator but I will return it to autozone to get my core back unless it can be used to determine it is defective. Over the years I have spent a lot at repair shops and the dealership trying to locate the cause of this. At the suggestion of the dealer service manager, I replaced the speed sensor twice over the years to "fix" the erratic speed at startup but without any change.

- Rockville, MD, USA

When turning on headlights the panel lights dim due to design, this results in difficulty in seeing dash components during daytime.

- El Cerrito, CA, USA