I think the switch needs replaced. It is located at the top of the brake pedal. Here is a picture of it and directions I found to help you replace it. It is a tight fit, but not hard to do. Just follow the directions and if you run into trouble, let me know.
1.Lift the locking tab on the switch connector and disconnect the wiring.
2.Remove the hairpin retainer, slide the stoplamp switch, pushrod and nylon washer off of the pedal. Remove the washer, then the switch by sliding it up or down.
On some vehicles equipped with speed control, the spacer washer is replaced by the dump valve adapter washer.
3.Position it so that the U-shaped side is nearest the pedal and directly over/under the pin.
4.Slide the switch up or down, trapping the master cylinder pushrod and bushing between the switch side plates.
5.Push the switch and pushrod assembly firmly towards the brake pedal arm. Assemble the outside white plastic washer to the pin and install the hairpin retainer.
Don't substitute any other type of retainer. Use only the Ford specified hairpin retainer.
6.Assemble the connector on the switch.
7.Check stoplamp operation.
Make sure that the stoplamp switch wiring has sufficient travel during a full pedal stroke.
Let me know if this helps.
Saturday, July 24th, 2010 AT 12:50 AM