Mondo 2010 electrical fault

[Muzzisben]

Hi all

I noticed my radio momentarily cutting out, at the same time, Speedo drops and immediately return to normal.   At the same time The abs esp and handbrake flash.  I have also noticed when going up the kerb to my drive all lights on dash flash and everything lights up.   I’m guessing something loose but don’t know where to start.  I have tested the battery with a very good tester and it came up faulty cell and replace.  Could this be the cause.

 

thanks

[isetta]

if the battery has enough power to start the car in the morning I doubt if the battery would be the cause of the problems. also bearing in mind you say a problem is created when you go over the kerb it would suggest a loose electrical connection. if the problem was the battery itself inside then I don't see that being affected by going over a kerb.

so it's checking every connector everywhere and checking every fuse and every relay is pushed in properly. I do not know enough about Mondeos to suggest where the most likely culprit is

[Westville]

First thing I would do is tighten up your earth lead where it joins the bodywork and make sure the battery terminals are clean and tight

[FatHead1979]

Modern cars a VERY sensitive to power/battery issues.  There have been a few threads in the Focus forum over the years where a "borderline knackered" battery has managed to start the car but the ECU has detected insufficient current and started to disable systems such as PAS.

 

On my MK2 Focus (a few years ago) I knew the battery was on it's last legs, I started to get more frequent glitchy behaviour, started the car successfully on a cold December morning and then battery finally dropped a cell at the end of my street, stranding the car in the middle of the road.

 

As per @Westville advice, I'd be checking the earth and battery points regardless of the "state" of the battery but if you know the battery is dying you can expect to see more and more weird behaviour from your car.

[Westville]

I've just swapped from a Land Rover Freelander 2 (shared Ford heritage) and the number of problems they have from battery related faults is no-one's business - the ECUs detect even the slightest fleeting drop in supply and play up presenting all sorts of weird symptoms.

Any weird electrical behaviour on those is usually due to poor earthing - (so much so that many now fit a 2nd earth strap) - and/or a weak battery. Domestic testing equipment will not detect the problem correctly I always advise people to get their battery professionally tested under load.

@1979Damian seems to have the same view