I have a 2008 f150 fx4 and the passenger side fog light will not work unless i tap the fog light. Once i tap it, it will work fine. Anyone else encounter something like this, what was the problem? I did hit it with the high pressure hose at the car wash because i had some mud on the inside of the bumber. Since than, i have had this problem.

 

Sounds like a ground issue to me

 

Could be a ground but may also be water in the plug also. I would check, clean and add a little dielectric grease to the plug and even replace the bulb both have caused that problem for me before.

 

^ what he said. If it stays on after you tap it, it most likely is just dirty contacts.

 

Corroded...clean and grease like JR said