Door switches work when they want to ; Fist they control the door locks and also the over head light ,Not bad when durring the day but at night total hell and hard as heck to see out when the lights come on inside i fixed a wire to the light so i could pull the light out when i was driving and it came on better then a reck witch i am sure has happend and or will happen but will ford pay for this ... I was told from the dealer that that was my problem and so i paid them to fix it well two days later the other one went out well two more doors i hope i will be done with this problem . Also this is not only for this ford F350 I have had 4 ford trucks and every one i had did all the same things ... What happen to the old style door switchs little botton in the jam never had problem with them never even think they ever replaced them I have over 500 cars and i bet i could get one off them and it will still work