One problem related to headlight switch has been reported for the 2004 Ford F-150. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford F-150 based on all problems reported for the 2004 F-150.
With headlight selector switch in the auto position the headlights can suddently turn-off while driving. I purchased the vehicle new and have always had the headlight switch in the auto position since day one. When driving at night the headlights suddenly shut-off while going down the highway, very nearly lost control of vehicle when trying to pull over and stop. The park lights still were functioning and got the headlights back on by switching the headlight switch to the manual position. Per discussion with dealer believe the body control module quit working. Specifically, a relay in the bcm has failed but is not replaceable. Repair cost is over $400. 00 to change module. Can't afford right now to fix. Research on internet found numerous other similar failures/symptoms but not clear if happened while vehicle was being driven.