2005 Ford Explorer

Electrical problem
2005 Ford Explorer 4 cyl Four Wheel Drive Automatic 780000 miles

I recently changed my spark plugs and I soon noticed my advtrac light is on. Could I have bumped or disconnected anything or is this unrelated? I worked in a GM dealership and still do my own work. What should I look for or is this a dealer only fix? Thank you, Scott Berger.
January 18, 2010.

I don't think they are related. Do you have a scanner? If so, scan the computer to identify where the problem is coming from. If you don't have one, most nationally recognized parts stores will do it for free. Chances are you have a bad vehicle speed sensor (VSS) at either the front or rear of the transfrer case.

Let me know what you find or if you have other questions.