Photo cell mod '03 Expedition

[djeuch]

This may work on other Ford trucks... please let me know if you have a similar setup.

I have always had the complaint that the automatic headlights don't turn on early enough... it has to be downright dark for them to turn on - probably 30-60 minutes after when I would like them on.

Ford has NO adjustment for this.

The simple change is to unplug the photo sensor (and thus also the red flashing alarm LED) and the lights always come on, but under bright sunlight, you can't see the dash any more.

Thus, the idea was born - what about a resistor to modify the photo cell sensitivity?

Once I took it apart, I came up with a much easier idea.

Required tools:

flathead screndriver (to pry the piece out)
Some sort of pliers
(optional) 1/4 in. hex screwdriver (can use pliers)
One hole punch (not the tool - the actual paper hole left over!)

Instructions:

First pry off the panel that holds the flashing red LED and photo sensor.

Use a screwdriver (short) and gently pry it up - clips are on the sides

Closeup

Screwdriver points to the plastic retaining clip - push it in to remove the connector

Remove the two hex screws to release the box from the trim piece.

 

[djeuch]

The inside slides out... (needs just a little force on the "dome" to release

Closeup disassembled

I removed the "dome" so have something to push on (later). Can be removed with a smaller flathead screwdriver on the one side...

 

[djeuch]

Here is the tricky part - as you can see, I've SERIOUSLY bent the plastic out of the way to get the circuit board to release... Unfortunately, I see no other easy way to do this, so proceed with caution. If it breaks, I think it can still be assembled fairly easily because the wires could hold it in place, but it might rattle.

Your 3 pieces

The green cap is directly over the photo transistor. Since it's a transistor, Ford could be using either tthe resistive side or non-resistive flow of current to measure sunlight, making my resistor idea a whole lot more complicated, potentially... but... easier method!

Underside of the cap along with the "hole" from a piece of paper (perfect size, I might add)

 

[djeuch]

Drop the hole in the cap, and then drop the circut board on top of the upside-down cap (so the hole doesn't fall out)

Pliers can snap the board back into place

Slide the pins carefully back into the holes on the other plastic piece

How it looks right before they snap together.

Position back on the trim piece and screw it back on

 

[djeuch]

How to put it back

Snap on the connector

snap into place

Modification complete!

Now I admit sometimes the lights come on when I'm in the shade on a not-so-bright day, but when that happens, the dash is still easily viewable.

I used one 20# white, unprinted "hole" - obviously more than one hole or darker colors will make the lights come on earlier.

Best part, it's completely under warranty still!

Enjoy!

 

[Keydo]

GREAT DIY instructions!

 

[monsta]

Man! That it a GREAT writeup!!!!

THREE thumbs up!

 

[on_a_mission]

good job bro

 

[Ray]

I read with interest your modification. I think it is a good one. But you nne to know that the new ones are much more sentive. My 2004 will auto turn on the lights at a dorp of a hat. While sitting under a bridge in bright day light the lights will come in in a coulpe of seconds. So Ford has made a mod. in the last year.