Hi new to posting so here goes . I use the speed control alot. i noticed a few weeks a go the speed control did not light up when i pushed the button. i tapped the brake and hit the switch again and the speed control worked. today i turned the speed control on. the light on dash flashed and then went off. the speed control won't work at all now, if i keep tapping the switch every now and then the light on the dash will come on for a second and go back off. help

 

Welcome aboard. My first guess would be the brake light switch. As you probably know pressing the brake pedal deactivates the system. Its possible that the switch is sticking for the brake lights which would cause the system to not work. Have you checked to make sure your brake lights aren't staying on at times? Another thing that you could try is to gently pull the brake pedal toward you with your left foot while trying yo activate the system, if that works then you've probably found your problem. If it is the brake light switch, they are easy to replace but just a little difficult to get to.

 

What year is your truck?
There is a major recall for many years and models of Fords concerning the cruise control switch on the brake master cylinder.
I posted concerning the recall on 6-14-2009;
https://www.ford-trucks.com/forums/8...se-recall.html
Ford Fire Recall: Update on Ford Fire Recall
FORD ANNOUNCES SAFETY RECALL | Ford Motor Company Newsroom

 

my truck is a 2004 lariat 4x4 hope this is problem.

 

Call the dealers service department and let them check your VIN# to see if the recall has been done. I recommend that you replace the switch anyway.
Amazon.com: Motorcraft SW-6350 Speed Sensor Switch Repair Kit: Automotive

 

thank you guys for the repllys i will go to dealer. checked brake light switch all ok there