I'm not sure what to call this issue, but when i was driving home yesterdayi noticed a clicking noise as if the lights where turn off and on and i could tell from the display that it was dimming and then going bright again. What could be causing this, i cannot locate the "eye" that detects light and darkness on my truck, it was almost as it something was waving over it making it come on and off. Any help would be appreciated.

 

Can you post the info on your truck or complete your profile.

 

Sorry about that, I have a 1997 Ford F-150 Supercab 4x4 140,000 miles!

 

The photocell should be under the grille on the top of the dash.

Start with checking to see if something is blocking, next would be checking the autolamp module.