I have an '06 5.9. The fog lights quit working then about four days later started working. They recently quit working again no power to bulbs, checked all fuses under hood and bulbs are fine. The manual doesnt specifically say which fuse is for the fog lights or if there is a relay. Any suggestions or know which fuse is for fog lights or if there is a relay?

 

They are controlled by the TIPM (computer under the fuse box) You'll most likely have to go to the dealer to get it cleared or "reset". Before you do that, check and make sure there are no shorts or problems with the wires. There's only a certain number of times you can reset the TIPM before it's toast and you need a new (Expensive) one.

ps - i can usually get them to do this for free - just go back and find the service manager and talk to him.