2003 f150 super crew pickup. Cruise control will stop working when on rough road. sometimes can hit the resume button and will start working again. sometime must reset the cruise control to get it working again.

 

Because you have to reset the Cruise Control sometimes, I would suspect an intermittent electrical connection in your brake lighting. This could be either in your two standard brake lights or in the third, center mounted brake lights. A failure in any of these circuits would render the CC inoperative. You might have a faulty ground connection on any of them, or, it could also be a connection in the positive feed. A rough road would "shake" the connections and possibly "break" the circuit.

The other possibility is the brake switch itself. Again, a rough road might activate the brake switch momentarily which would cancel the CC. But, if this were the cause, I would expect it to reset with "Resume" all the time.

Others may have better thoughts on this, so don't be surprised if they chime in.

- Jack