Only one headlight comes on????

[HRivera]

i have a 07 sport track limited edition. so one night my driver side headlight did not come on. the thing that threw me off was the high beams stilled worked i assumed it was the bulb but when i changed it nothing. so i checked the fuses and everything is working. so i took a light tester to the socket and found that no power was making it on low beam. so i packed up and took it to an electrician. what he came back with was that it is the smart computer that controls the lights when you turn the switch to the left and put them on automatic on/off. ( did that make sense?)

so my question is : has anyone had the problem where only one headlight comes on or only work on high beam ?

recap : all fusses good / only low beam driver side does not work / could the smart computer be to blame?

any help would greatly be appreciated.

 

[JohnnyO]

The low beam can burn out and the high beam will still work. I never heard of the computer cutting the power to one light but then I'm old-school. Low and high have separate filiments, it's not like the bulb just gets extra power when you turn on the high beams.
Try swapping the bulbs from side to side and see what happens. My money is still on a burnt out bulb.

 

[Austin77]

I have seen this happen to multi-plexed hwy tractors, I'm pretty sure there is a headlight module, and if there is then it needs to be replaced (atleast thats the case in the multi-plexed hwy tractors I work on)

 

[GreenMando]

so my question is : has anyone had the problem where only one headlight comes on or only work on high beam ?

Yes, but I have not experienced it on my Sport Trac yet. It occurred on my Ford Bronco, I had to replace a headlight module, a relay of sorts.
I would try the headlight switch itself if the truck is not too old.

 

[HRivera]

differently not the bulb that was the first thing on my mind.. im thinking it might be the headlight module or how ford refers to it the "the smart computer" it is under the steering wheel and is one hole piece with the fuses down there.