coachk64

On my 1996 F150 with a 302 I have the button at the end of my gear shift lever to turn off the overdrive, which is accompanied by an illuminated "Off" when it is pressed. Just yesterday that illuminated "Off" started flashing. It will flash about once a second while driving through city streets and accelerating up to highway speed, then it will mostly go off, only coming on every now and then. The flashing doesn't seem to be connected to which gear I'm currently in, and will sometimes come on when I'm coasting to a lower speed, when I should definitely be in overdrive.

When it is unlit, I can press the button turning the overdrive off and illuminating the indicator and I can feel the transmission down shifting, then going back into overdrive when I press the button again, turning the overdrive back on, and shutting off the indicator.

A couple of times while coasting and the indicator was flashing I thought I could feel the transmission going into and out of overdrive.

Where should I start looking?