I have a 2016 Mondeo 1.5 Zetec estate and the heated front screen is not working.

I now know that this (and the stop start function) depend upon a battery in tip-top condition to work properly. Replacing the battery (which I have done twice) or going for a long drive can make them work again. But after a few short runs they stop working again.

I took it to my local garage who initially advised a new screen which was replaced BY A RECOMMENDED CONTRACTOR for the princely sum of £250. This did not work. So they took another look and said that the battery needed replacing and took £200 for the privilege. This worked for a short period but now it has stopped working.
I think there may be a charging issue that is not fully charging the battery.

I spoke with them today and they said that could put me in contact with an auto electrician who is also an INDEPENDENT CONTRACTOR as they “don’t do” electrics. For £150ph+VAT. I pointed out that I’d spent £450 with them and they pointed out that the only money they’d seen was the £200 for the battery!

Is there a common charging issue with these cars?

Any suggestions?

Thank you.

4 minutes ago, Doc007 said:

Is there a common charging issue with these cars?

For only £195, I can answer that question, and at no extra charge even tell you how to solve the issue. 👍

Do you own a Maypole (or similar) Smart battery charger ?

On 2/17/2025 at 8:30 PM, unofix said:

For only £195, I can answer that question, and at no extra charge even tell you how to solve the issue. 👍

Do you own a Maypole (or similar) Smart battery charger ?

Hi Unofix. I have a CTEK charger. I put it on over night and it didn’t resolve the issue. What is the likely cause of the problem? It seems I’m not the only Ford driver to fall foul of it!

15 minutes ago, Doc007 said:

Hi Unofix. I have a CTEK charger. I put it on over night and it didn’t resolve the issue. What is the likely cause of the problem? It seems I’m not the only Ford driver to fall foul of it!

Did you connect the - lead on the correct side of the  BMS sensor ? Did you reset the BMS system when you charged the new battery ?

On 2/18/2025 at 9:07 PM, Delboy777 said:

Did you connect the - lead on the correct side of the  BMS sensor ? Did you reset the BMS system when you charged the new battery ?

The garage fitted the battery. What/where is the BMS and how do you reset it? If I charge the battery would resetting the BMS work?

1 hour ago, Doc007 said:

What/where is the BMS

It's part of the battery negative clamp.

1 hour ago, Doc007 said:

and how do you reset it?

The procedure for resetting it if you fit a new battery will be one of the two options shown in the videos below

1 hour ago, Doc007 said:

If I charge the battery would resetting the BMS work?

Not sure I quite understand the question. The BMS needs reset if a new battery is installed. It won't fix anything on it's own. A fully charged new battery (yes you need to charge a new battery before installing it) will get the heated screen working provided the ambient temperature is below 7^oC

Stop/Start might work, then again it might not. It is designed to work (or not) when the vehicle decides all conditions are correct. That's approximately 112 individual parameters that need to be in the Goldilocks state.

On 3/29/2023 at 8:13 PM, unofix said:

How to reset the BMS method 1                                                                         Search Tag: BMS1

 

 

On 3/29/2023 at 8:14 PM, unofix said:

How to reset the BMS method 2                                                                         Search Tag: BMS2

 

 

I’ve tried charging and resetting the BMS. Fingers crossed. Unofix, if charging/jumpstarting does the presence of the BMS mean that you have to attach one of the electrodes to a specific part of the clamp?

When using a battery charger:

• connect the positive lead (red) directly to the battery positive terminal +
• connect the negative lead (black) to the chassis earth point, not to the battery terminal.

Follow the big heavy black cable from the battery negative post, and in less the 400mm (15") the big heavy black cable will be bolted the the car body. That is the chassis earth point, the place to connect the negative lead of the battery charger.

On 2/20/2025 at 10:41 PM, unofix said:

When using a battery charger:

• connect the positive lead (red) directly to the battery positive terminal +
• connect the negative lead (black) to the chassis earth point, not to the battery terminal.

Follow the big heavy black cable from the battery negative post, and in less the 400mm (15") the big heavy black cable will be bolted the the car body. That is the chassis earth point, the place to connect the negative lead of the battery charger.

Thanks Unofix. I resent the BMS and the Stop/Start is now working! Too soon to say it’s been fixed but it’s promising…