Hi, I have a 66 plate Ford S-Max 2.0 Deisel Titanium, A couple of moths ago Both heated front and rear screens stopped working, start stop has stopped working, Radio only works when it wants ( if I lock then unlock the car sometimes the radio works)and revesing beeps has a higher tone. I had a local garage check it over, and they told me to take it to Ford.  Ford pluged it in to their diagnostic machine and said all is working ok, they kept it for as couple of days when it was cold and could see it wasnt working, but couldn't come up with a solution. Any advise would be great.

Sounds like a low battery to me. 

Got it booked in to Halfords tomorrow to have the battery checked. Lets hope it is that.

I wouldn't do anything until you've tried resetting the battery monitoring system. In most cases like this, it's the way the car is reporting low battery charge that is the problem, not the battery itself. Hopefully Ford might come up with a long term solution one day. There seems to be two manual methods.

Deadwing said : Try this,

The Battery Monitor Sensor can also be reset manually by using the following
steps:
• Switch on the ignition.
• Press the high beam switch five times by pulling and releasing.
• Press and release the brake pedal three times.
• If the steps were successful, the warning indicator of the battery charging system in the
IPC (instrument panel cluster) flashes three times within the next 15 s.
If the sequence is interrupted by pressing other keys or pedals for any reason, repeat the
above steps, starting from the beginning.
 

If the BMS reset procedure described above does not work, follow the procedure
below (within 10 s):
• Switch on the ignition.
• Press the rear fog light switch five times.
• Press the hazard flasher switch three times.
• If the steps were successful, the warning indicator of the battery charging system in the
IPC (instrument panel cluster) flashes three times within the next 15 s.

Funnily enough, I tried both methods given by Deadwing a couple of weeks ago, the first method described as being for the Fiesta, the second for the Focus. I wasn't having any problem as such, but nearly every time I got in the car I had the timing out bar telling me to start up or it would start shutting things down. Every time this happened, the nav screen went to the Home screen rather than how I left it. Anyway, neither method seemed to do anything, I didn't notice the battery light flash, BUT, I have not seen the timing out bar since! I just went out and tried again, and this time method 1 worked, and after a few seconds the battery light flashed 3 times. Whether this has in fact reset the BMS, who knows? But will keep an eye on things and report back if anything interesting.

So the exact method I used :

Gear in neutral, leave clutch pedal alone, press Start button.

Put light switch to Headlights, flash main beam 5 times.

Press brake pedal and release 3 times.

Wait a few seconds until battery indication flashes on and off 3 times.

Switch off ignition.

Just tried both these methods. they didnt work. car now won't start. Think the battery is dead. just called the RAC

All sounds familiar!

Have you had it back in for the recall to fit the fuse loom on the battery monitoring sensor?