The car is 11/12 years old and if still running on the original battery it would be a good place to start. Might now b struggling to hold its charge when the colder weather hits.

 

Do you know how old the battery is? It'll either be that or the Alternator not supplying enough current to it.

 

All that electrical load on at once will be a huge current draw. If you do an alternator test on a healthy alternator and battery at idle, it will likely fail the test as they can't keep up with the current draw at idle, with the front heated screen on as that's the biggest power draw.

If you do have a poor battery then it most definitely wont help at all.

 

I would change the battery for sure

Euro Car parts do a good voucher offers , so get a descent Bosch, lithium-ion one with 5 year guarantee

 

The alternator needs to be spinning at a certain RPM to start charging when you start the car. With all that current draw and if the engine hiccups the charging may cut off and not start again intill the initial RPM is met by the alternator again. His the light remained on or did it go out when you revved the engine?

 

The thing that got me here was that you left the car ALONE to warm up whilst turned on!

Do you actually want to have it stolen?

 

Also ilegal if it was on the road.
Andi.

 

Mk3 Mondeo TDCi's have some sort of electric aux heater built in that comes on below certain temperatures which i believe is a bit like a glow plug. That along with all the above will have been drawing some epic current.

If it's the original Motorcraft battery it'll have a first charged date stamped on it.

 

Wasn't going to mention it as seems common practice for most nowadays even though makers say start the car and drive away. Insurance do not pay out if the car is taken either when left like that.

 

Depending on location, I'd never leave my car alone in London where I lived.. but where I live now there's not a soul awake or anywhere near my car..

 

As long as you lock the car it's a minor.

 

Always let my car warm up while I go eat my breakfast, It's on my driveway, it's not going anywhere....TBF I do live in a more remote side of my town where the street consists more of the older generation.

 

It really depends where you live, i do it any day its been frosty as i have a big driveway where you can't really see the cars from the road and we also live in the middle of nowhere.

If i was living in the center of Manchester i doubt i'd do it

 

Why leave the headlights and radio on if the car is being left to warm up unattended?

 

A little fact on the focus TDCI that may apply to the Mondeo too - there are two alternators you can get (the cheap one and the more expensive part) for the titanium trim with all the gadgets etc I needed the higher power one but the first replacement they used the cheap one. I found that out when I fitted the second one myself and the cat seemed far more with it (faster charging etc).

The battery and alternator seem to kill each other off if one dies, so you may as well replace the battery if the alternator is putting out enough power (iirc it was 15V or so across the battery terminals). Measuring current is far more difficult (needing a clamp meter).

Hmm not sure about an aux heater - perhaps in cold climates (Norway for example) but the ford front window that has a heating matrix in it sucks power - same as the heated seats and the air heater matrix.

In Norway they have a remote for starting and warming up the car from the house