Hi, 

I have a Focus which, intermittently, completely electrically dies. My local electrical specialist garage is totally confused. Any thoughts would be very welcome! 

The story begins (perhaps) in April 2022. Out of nowhere, after a couple of days being stood on my drive, my 2014 Focus is totally electrically dead. I mean, totally - it won't even unlock on the fob, and literally nothing happens when I get in and turn the ignition. However, as soon as I connect it to another car, to jump start it, all the electrics leap into life, and although the engine is initially still dead, after 20 minutes connected to the other car, I can start the Focus and drive it as normal. Easy, flat battery, right? 

Well, yes and no. It goes to the local garage, and although the battery is a bit low, it otherwise passes the tests - the battery is healthy, the alternator is working, and there's no persistent electrical drain. The garage charges the battery, sends the car back, and within a few days, the same thing happens again. The garage concludes that the battery is faulty, replaces it, and everything is fine for 9 months - and perhaps this was a stand alone episode, and what happens next isn't connected... 

However, fast forward to January 2023. Precisely the same thing happens again - the car won't unlock and is electrically totally dead. The only slight oddity is that, while the car doesn't unlock, the boot door opens, almost as if that's been left unlocked. I jump start it, run it to the garage... And nothing is wrong, except the battery is a bit low again (but should have enough juice to work). The garage recharges the battery, and sends it back, working on the premise that we left the boot open by mistake, and it drained the battery to a critical level, which then got recharged on the (short) run to the garage. 

It works again for a week or so, then one fine morning in February, is dead yet again. I jump it and take it to the garage. This time, the battery shows as fully charged, and once again it passes all the tests with flying colours. The garage changes the earth leads, and sends it back. I'm woken up early the next morning by the alarm going off, repeatedly - and although I can initially lock/unlock it to stop the alarm, on the last occasion the car is once again dead. This time, when I come to jump start it, all the doors apart from the boot are unlocked. 

It's now been at the garage for two weeks. They haven't charged the battery or done anything to it, other than check its power level; they simply check the car twice a day, and every time it unlocks/locks and starts like a perfectly healthy car. They've checked the main leads and can't find anything wrong. They're as frustrated as I am - in all the garage visits, they've not seen it go wrong once, but I keep finding it dead on my drive. 

I don't suppose anyone has come across this before? I'll need to take the car back soon, and if it happens again, I might be ringing an exorcist rather than the garage... 

Many thanks. 

8 minutes ago, Southdunedain said:

I don't suppose anyone has come across this before?...

I have actually experienced exactly the same thing, except, it was with a 2003 Mercedes C240! Like you, the garage ended up having it for several weeks and annoyingly it behaved perfectly.  Once collected, it started being naughty again. I'm afraid I sold it in the end as it was plagued with electrical gremlins which no one could ever get to the bottom of, even the replacement of a SAM box, (merc equivalent of a Ford GEM controller)

Hope someone else is able to help as there's nothing more anxiety causing than going to your car constantly wondering if the darn thing will open, never mind start!

3 minutes ago, StephenFord said:

Hope someone else is able to help as there's nothing more anxiety causing than going to your car constantly wondering if the darn thing will open, never mind start!

Thanks! Tell me about it... My wife's patience has long since been expended, and although I'm more laid back about such things, I'm getting close to breaking point too! 

Has the Body Control Module (BCM) been inspected for signs of water ingress and/or corrosion of the connectors ?

I'd also recommend that the vehicle is checked for possible Diagnostic Trouble Codes (DTC's) using FORScan and NOT a generic code reader no matter how good or expensive it is.

The latest problem with the alarm system is a classic fault of water ingress to the BCM.

20 hours ago, unofix said:

Has the Body Control Module (BCM) been inspected for signs of water ingress and/or corrosion of the connectors ?

I'd also recommend that the vehicle is checked for possible Diagnostic Trouble Codes (DTC's) using FORScan and NOT a generic code reader no matter how good or expensive it is.

The latest problem with the alarm system is a classic fault of water ingress to the BCM.

Thanks. I'll ask the garage about the BCM.

It's not flagging any errors at all as far as I can tell, as the driver. I'm used to it at least throwing up an info/warning light or dashboard message. I presume there could still be DTCs sitting in the background? 

The problem is that if you are not using a Ford main dealer for the diagnostic work then there is a very good chance that an independence garage will just use a generic code reader and not all Ford specific DTC's will be read.

If you have a Windows laptop then I would recommend that you check for any DTC's yourself using FORScan.

Have you found the fix for this or have an update. Im having the exact same issue. 

Ah, but have you followed the advice above, looked at the BCM  for any evidence of water damage etc and used Forscan to read any codes? (Just my cheeky 5p worth, sorry!)

3 hours ago, Shearers said:

(Just my cheeky 5p worth, sorry!)

That's a sign of inflation. I usually only put my tuppence in !! 🤣

2 minutes ago, unofix said:

That's a sign of inflation. I usually only put my tuppence in !! 🤣

I'm really tight, I never give more than my penny's worth! LOL

Hi all. I had this problem too. Might be worth checking the windscreen scuttle drains that are meant to take water from the windscreen out via the wheel arches. Mine was blocked with leaves causing ingress onto some of the electronics. Took several garages to work this out (after I'd bought a new battery too...)