04 f-150 xlt, bought new switch still does not turn on at dusk.

 

Oh I can help you here my friend! I will definitely say it has to be the auto lamp relay in the body security module gone bad. It is located behind your rear seat, driver's side. There is a blue plug going into the bottom of the BSM, if you unplug it I'll bet you one of the pins is black and melted. Mine is and it shorted out my relay which is why mine doesn't work anymore! eventually I'll replace and reprogram it and never use the autolamps again. That circuit draws a lot of heat and can melt that pin or cause a short in the BSM itself. Ebay has a bunch for $100 and then you'd have to go to the dealer to reprogram the BSM for everything to work properly.

 

Can the relay be replaced without reprogramming?

If you don't use the auto light feature is there any more damage to the body module?

Bernie

 

The relay is soldered onto the board so no. And no, usually there's no further damage to the module if you don't use that function.

 

thanks