Is your local garage worth shouting about? We want to hear about it. | No thanks
Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving  
Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

when i was driving last week my battery light was staying,then my abs light came on and my dashboard lights dimmed.

i pulled over then turned engine off to phone home,tried to start engine again and would not start,i got rac out and they suspected altenator as it was only reading 8.2 volts on meter.

i got it replaced plus a new fan belt and for a couple of days it was fine,but now the battery light is back when driving and my front demister will not work,car is driving fine though.

any ideas what problem could be.

Tags: technical issues batteries warning lights starting ABS

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - jc2

It is common for many electric circuits-particularly ones with high load-to be wired so they only work when there is alternator output.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - daveyjp

"any ideas what problem could be."

Did the RAC do any testing of the battery, other than check the voltage? If the battery is on it's way out, which at five years could be possible, a new alternator won't make any difference.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

battery has been checked at reading 12 volts,engine turned on and showing 14.4v .

when i go out in morning i switch engine on and due to heavy frost here my front/rear demisters come on,then after a min the front one goes out and battery light comes on,front demister will not operate because this light showing.

i then drove 1/4 mile to shop turned off engine then start again and light goes out,travelled 30 mile to work and car fine.

baffled with this problem.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Collos25

Normal cause is a diode in the alternator breaking down,it will do no harm if you can live with it if not I am afraid it looks like an alternator change unless you are handy with a soldering iron.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - jc2

Two things:-

1. Where did the replacement alternator come from?

2.Is it a calcium battery?

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Avant

Moved to Technical.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - elekie&a/c doctor

These Mondeo models use a smart alternator that is controlled by the engine management system.I would think that the system has gone in to failsafe mode which means that it will charge at a steady voltage rather than variable programme.When this happens ,heavy consumers like hrw/hfw are shut down.I would suspect that either the alternator is at fault,or there is a problem with the wiring.hth

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

been to garage,they have checked everything and have decided to replace alternator on mon,so hopefully that is the root of problem.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - over30
Test the battery with a multimeter.

Contrary to what many people think the battery should not read a plain 12volts.

If the reading is less than 12volts, then the battery is discharged

Anything less than 12.4volts on the multimeter indicates a partially discharged battery.

If you are getting at least '14volts' across the battery terminals when the engine is running then the alternator is doing its job. And is certanly NOT FAULTY!


Dont pay a garage to replace the alternator, Replace the battery.

Car batteries are only guaranteed for 2, possibly 3 years.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Collos25

How will replacing the battery have any effect on the ignition light ,everything works as normal only the light stays on according to the poster.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - over30

The battery warning light usually illuminates because the charge level in the battery is too low.

A faulty earth connection to the chassis could also cause intermittent electrical problems. This can cause problems such as non starting, and intermittent stalling

If the battery is above 3 years old, it is more than likely that it is worn out, the increased strain of using 'Heated screens', 'blowers' etc, will show up problems with an old battery especially in winter.

The alternator is doing its job (14volts + across the terminals when the engine is running)

The battery is not holding its charge, hence the 'battery light'

If the battery is knackered which I suspect it is, then it will not charge correctly regardless of what the alternator is doing.

Edited by over30 on 27/11/2010 at 20:35

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - elekie&a/c doctor

A charge rate of 14v is perfectly ok on a standard alternator system.However the Mondeo uses a smart charge system that allows the charge voltage to rise to almost 16v under certain conditions .That is why the system uses a smart control system via the engine management unit.This analyses command and monitor signals via the extra 3 wires connected to the alternator.If the alternator regulator is faulty,it will charge at a default volts of 14 v but the electronics will not satisfy the parameters of the engine ecu to extinguish the warning light.I looked at a mondeo recently with exactly the same symptoms and the fault was within the alternator.hth

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

so what are you saying is it defo the alternator that should be replaced as im due to get it done tomorrow night.is the regulator part of the alternator????

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

i have now had a replacment alternator put in the car and battery light is still showing on dashboard.it seems to be when i turn engine on and cold outside the front and rear demisters come on for a couple of minutes then battery light comes on and front demister goes off and will not work.the only way i can stop this is when i turn engine on and turn off demisters right away and that seems to solve the problem.

any ideas folks,this is bugging me now

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Collos25

Something is keeping it in safety mode which limits the output of the alternator,is it a new proper for the car alternator.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - fordman1

How long has the battery been installed in your car?

Has it been more than 2 years.

Test the battery with a 'multimeter', and let us know what readings you get after the following checks:

1. test the battery after the car has been stood for several hours.

2. test the battery whilst the engine is running.

3. test the battery with the engine running, but with everything electrical switched on

A loose or faulty 'earth' connection could also cause the battery light to illuminate.

Edited by fordman1 on 29/11/2010 at 20:47

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - elekie&a/c doctor

The 3 control wires connected to the back of the alternator need to be checked.One wire (usually red or orange) is the battery voltage permanent sense circuit.The other 2 wires are for the command and monitor circuits back to the engine ecu.These can only really be tested correctly with a scope.The alternators that are being fitted,are these genuine parts or aftermarket?hth

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

this is not a genuine ford part getting replaced,it is a n aftermarket.

after my original problems a replacement alternator was fitted fixing probs,then a few days later battery light was coming back on.garage checked most things,but decided they should replace alternator with another as they suspected maybe a fault.got it changed last night and was not even out the forecourt and it appeared again.the only way it is not showing on dashboard is if i turn front/rear demisters off as soon as i start car.if i leave them on the light will come on and front demister will go off and can not operate.

as for the history of the battery i have only had car for 3 months so i do not know how long battery has been in car.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - elekie&a/c doctor

Many of the aftermarket reman alternators do not work correctly on these.The voltage control is critical on mondeos and often only the Ford replacement can offer the quality components for the system to operate as it should.However ,you do need to get the 3 sense wires tested correctly and if the garage does not have the special tester or scope you are going to round in circles.hth

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - jc2

I asked about the alternator on the 24th.- I was never answered!

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Collos25

I think the answer is that the proper alternator is not being used and or the fitters are not qualified to rectify the problem . The tests to make sure everything is ok are clearly stated in an above post but do not seem to be followed, just like question above the answer was not forthcoming.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

first off all andy im new to this website so still getting used to it,secondly ford charge through the roof for their genuine parts and i dont have that kind of cash,third is the so called fitters are trying there best to rectify it but im only trying other options to get this rectified.if it really bothers you that i dont answer every question then dont reply to mine thanks.i will get my answers else where.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - jc2

Ford genuine parts may cost more than pattern but they do work.By the time you've tried all these other options,you'll have spent more than the genuine part.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

iv only spent on an aftermarket alternator so far but fingers crossed they will fix shortly,will let you know mate

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Collos25

www.absolutely-starters-alternators.co.uk/html/for...l

Dug this out didn´t know I still had it, this is the company I used to use fitted many to Jaguar x type 2.0\2.2 diesel they were plug and play I think around 100ukp.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

andy,iv already shelled out £100 quid on a new alternator and then they have replaced that one because they thot it could be faulty.but the fault light still there.its going back in thur night/fri so they can try an early morn start to see what i was getting.will let you know outcome.

thanks for link anyway

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - quizman

I've had the same problem on my combine.

My mechanic replaced the original alternator and the dash light stayed on, but the battery still charged itself. After several hours he found that the wires were on the wrong terminals. He swapped them over and everthing was OK. I must say that the terminals on the new alternator were slightly different from the original.

So my advice is to check the wires are on the correct terminals.

And don't be nasty to Andy, he gives good advice.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

no probs,car going in tonight,will let them know,will let you know outcome.

cheers

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Enginostics

Hi, i have just read through the whole of the thread regarding your battery problem. We are specialist in the field, having a BEng in Electronics and having worked in the rally industry for a good few years. We have come across this problem before, here is what you need to do/have done:

1) Look at the grounding points scattered around the vehicle, check the cables using a multimeter. Unscrew the ground points, clean the terminals down to metal and do the same where the terminal mounts. You'll notice that the terminals in some places mount onto paint work. Rub the this area down to bear metal, remount ground terminal and copper grease over it. Check the resistance between each ground point and the negative side of the battery.

2) Using a Oscilloscope, we use a Fluke 124 and a Picoscope Automotive, check the battery and alternator. These vehicles have a smart charging system as rightfully mention previously by someone on here and can ONLY be checked using a scope and someone who knows what the scope should be reading. Use the scope to also check if there is any ripple leak out of the alternator. This is very important as any AC voltage in the DC line will cause gremlins to be blunt.

3) I would also check the demister circuit for a short or a large current drain.

4) The charging system is controlled by the engine control unit (ECU), which should be checked by Ford and software flashed if needed. This is a common fault, as the software used by Ford is somewhat........well, it speaks for itself!

Let us know on here how you get on.

Enginostics

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

after all the visits to my garage car has now finally been fixed and battery light now disapears when driving.

the problem came from not using a genuine ford alternator and going for the cheaper option of using an aftermarket one.

i had to pay an extra £70 but car is cured and im happy.

so i would like to thank everybody who commented on this topic for all there info and very much appreciated and i will use this again.

and thanks again for all the ones who mentioned the alternator in the first place especially andy.

merry chirstmas

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - Collos25

Great news bet you feel relieved now that little episode is over.

Ford Mondeo 2.0 tdci 130 2005 - battery light stays on dashboard when driving - keith72

yes andy glad its done,it just goes to show that if you spend that wee bit extra on a dealer part it would probaly save you the hassle going to a garage every few days,but its fixed and im happy and if it helps others in the future

thanks again for your input,cheers again.

keith

Join the discussion

Latest News & Road Tests

Buying Advice

Honest John's Newsletter

Connect with Honest John

Facebook YouTube