hey guys I'm having problems with my cruise control... sometimes it will not turn on and other times I will have it on and after a couple mins. it just shuts off and I can't get it to turn back on. Does anyone have an idea of what could be causing this?? thanks

 

Take a look at the switch on your master cylinder, see if it might be leaking. Sounds like a switch of some kind.

 

Thanks Bluejay I'll have to take a look at that

 

Is your 2004 a Heritage or Lightning model ?
Couldn't find a post from you that shows that it is, assuming it is not.

If not, the next question is did you do a LED taillight conversion ( rear and/or CHMSL ).

2004 -2008 the CC does not have the secondary safety switch on the master cylinder like the 97-03 MY trucks did, due to conversion to throttle by wire ( and the obvious reason Ford went away from this ).

There is a deactivator switch above the BPP ( Brake Pedal Position ) Switch on the brake mount. The BPP has 4 wires ( stop lamp, and Shift interlock ) to it, and higher up is the deactivator switch with 2 wires. Could be an issue with this, have you done any work under the dash as of late ?

If the CHMSL does not work all the time, this can cause an issue with the CC.
The PCM takes the input from the BPP ( CHMSL part ) and the deactivator switches for the CC. Usually standard bulbs in the tail lamps and a LED CHMSL together will be enough to run the CC ( mine is an aftermarket LED CHMSL on the cap, with std bulbs ).

If you have a manual trans, the CPP ( Clutch Pedal Position ) Switch also is an input to the PCM.

The PCM controls the ETC ( Electronic Throttle Control ) motor, and confirms the placement with the TPS ( Throttle Position Sensor ). Bit different on the 4.2L, this is a 5.4L & 4.6L configuration.