I have a 1997 F150 4x4 5.4 111,000 miles. Vehicles has been well maintained and not abused. Recently, the IAC valve started making a whistling sound. I am changing this saturday. Two weeks ago while driving around 60mph, the OD light started flashing. I pulled over and checked everything and restarted the truck. Light went out but started again. Stopped and this time the light went out. Drove approximatley 100 miles and the light did not come on. Problem is now the OD off button won't come on... Any clues

 

This is the pre-1997 Forum (1996 and older).
You might want to post over in the 1997-2003 F-150 Forum.