Hello,

I've got a 2015 Mondeo and the start/stop and heated windscreen are not working.

The start / stop used to work but is currently greyed out and does not work. At first when I turned the AC off it started working again but now it does'nt work with AC on or off.

As far as I remember the heated windscreen has never work.

Do you think I should try replacing the battery as I've had the car 5 years and am guessing it may be the original battery? (9 years old)

Thanks. 

 

Battery

Your battery state of charge is low.

Charge the battery for at least 12 hours using a Smart battery charger. Remember to connect the negative charger lead to the chassis earth point, Not the battery terminal.

Just checked the battery and its reading 12.20v which would explain why its not working.

Is it worth charging it or will it just go again with the age of the battery?

sorry, what is "chassis earth point, Not the battery terminal"

All Ford cars from about 2013 are fitted with a Battery Monitor System (BMS) which is fitted in the negative battery lead. In order for the system to be able to recognise that the battery is being charged the negative lead of the battery charger must be connected to an earth point on the vehicles chassis/body. If you were to connect the negative lead of the charger direct to the battery terminal then the BMS would not know that the battery had been charged and would not reinstate equipment that had been turned off to save power.

Also all modern cars now use a Smart charging system which limits the cars alternator to charging the battery to a maximum of 80% of it's capacity. This is all to save the dolphins and to keep Greta happy. As you battery ages it is unable to hold sufficient charge, and rapidly falls below 69% and things start to get switched off to save the battery State Of Charge.