Adjust headlight auto-on threshold?

[Rick Ohnsman]

I believe increasing my vehicles visibility on dark days and wish my '03 ST had daytime running lights, (as I'm told is the law in Canada and Europe, yes?). The lights do come on by themselves, but it has to be quite dark. Of course I can always switch them on manually, but what I'd like is to be able to adjust the threshold of the auto-on feature so that it doesn't have to be quite as dark for them to switch on. Is this possible?



It occurs to me that there is probably a photo-sensor somewhere that is the actual trigger for this feature. Where is it? Perhaps putting a small piece of tinted material over that might "fool" the sensor into thinking it was darker than it really is? Thoughts??

 

[Dan Long]

Most are built into the base of the rear view mirror where it attaches to the windshield. If yours is the same, which I think it is, the tint should work fine. I have read about an adjustment being possible, but I've never tried it or even looked to see if the button is there. What I remember is they said you push a button through a small hole on the bottom of the mirror, then use the delay slider to adjust the sensitivity.

 

[Nelson Atwell]

The sensor is on the dash. I found this out by accident one day when I laid a folder on my dash. It covered the sensor and the lights came on. You can get DRLs by covering this sensor permanently.

 

[Rick Ohnsman]

Interesting concept Dan. Anyone with an ST service manual that can confirm this is an adjustable setting and give a precise "how to?"



Thanks gang - Happy Trac'ing!

 

[Dan Long]

This procedure came from the older Explorer's with the auto-headlight option. I don't know if all of the ST's had the sensor in the dash, or if this came about with the dash 04-05 update. I installed an Explorer mirror in mine to gain the feature, as I didn't have it as a factory option, so I can't say for sure.

 

[Dan Long]

I just found this on a Ford Truck forum by doing a Google search:



You can adjust the sensitivity, I had to adjust mine for the same reason.



Here is the procedure for 1st gens (square mirror):

Move the autolamp delay slide knob to the far left with the tranny in park and ignition in the "run" position;

Press the mirror dim and autolamp on switches at the same time. The autolamp on led will flash when it is in the adjust mode;

Slowly slide the autolamp slide knob until the dim led is on steadily. This indicates the current setting, factory setting should fall in the middle;

To turn it on earlier, slide to the left, for later, slide to the right. The led will start flashing indicating the setting has changed. Press the autolamp button will enter the new setting and return it back to normal.



For oval mirrors:

There should be a small hole either on the bottom of the mirror just left of the word "autolamp" or possibly on the back of the mirror. With no hole, I believe you use the "mode" button.

Slide the delay switch to "off" (all the way left) and turn ignition on but not running;

Press and hold the mode button with a paperclip in the small hole and slide the bar until the lights come on;

Slide the bar left to come on earlier, right for later. Release the mode button and turn ignition off.

 

[Richard L]

The early model had the sensors built into the back of the rearview mirror. I had a 2003 Sport Trac that had the same problem. The lights would not come on until it too dark.



To solve the problem I taped a small square of dark limo-tint film over the sensor with scotch tape and it worked fine for the 5 years I owned the truck.



Do not put 2 layers of window tint over the sensor if you have the electronic dimming rearview mirror (which I think was part of that same package) because the auto-dimming mirror uses the front and rear sensors to determine when it's night time and when headlights from behind you are being detected in the mirror. Two layers of will cause your mirror to dim during the daylight.



...Rich