Hi

Focus 1.0L Manual Mk4 pre facelift (UK 69 Plate)

Had it 7 months, nice car but a flat battery after a month (fitted a new one).  Just happened again (battery swapped under guarantee).  I do not drive that much but am concerned that there may be an underlying cause.

• The RAC clamped a meter on the black cable to confirm that the battery was dead.  Also said that normally (with everything off) the draw on the battery should not exceed about 50 milliamps.  Can anyone recommend (a less expensive but sufficiently accurate) meter that I could buy to check for any parasitic drain?
• The SYNC is at 3.4.23188 and I have had a USB stick plugged in with music tracks.  I assume when the ignition is off this will not draw any current?

Regards

ASW

6 hours ago, ASW said:

I do not drive that much but am concerned that there may be an underlying cause.

100% totally normal. You need (like everyone else) to charge the battery every 5 or 6 weeks using a Smart battery charger.

 

I have a UNI-T UT210E AC/DC clamp meter with a 1mA resolution. Of course the accuracy is not within 1mA but more like 7-10mA, but on my Ford I know the current drain with all ECUs sleeping is around 34-40mA. So it is within spec.

Note that the car does not sleep imediately after locking it. Leave it some minute (ideally more than 40) and don't be surprised if some ECUs wakeup a few times to run some checks.

If after 40 minutes you have more than 50mA drain, there is an issue.

I have the same one, UNI-T UT210E. 

If you do get that one it defaults onto AC Current measurement so you have change it to DC every time, and you need to open the Bonnet, close all doors and not open them again while you wait for the car to go to sleep as RaduF said or it will wake up gain and give you a false reading.

Many thanks for the responses, have just ordered a UNI-T UT210E AC/DC clamp meter ...

On 11/26/2024 at 4:41 PM, RaduF86 said:

with a 1mA resolution. Of course the accuracy is not within 1mA

I like this - someone who knows the difference between resolution and accuracy !

Oh, and I forgot to mention, after locking the car (with the boonet open) take the key away from it if you have the keyless entry, and when you get close to read the meter, make sure the key is not on you or close to the car.

An old trick I used, was to measure the voltage drop across the earth lead, ie battery -ve to chassis.  It should only be mV, but you can "calibrate" it by putting a known load between the battery +ve and chassis.

Perhaps this technique could be used on a "modern" (overcomplicated ?) charging system.  One advantage may be that you can attach a pair of leads to the battery -ve and chassis, and shut the bonnet and lock up.  I have a DVM, with an ability to monitor/record the volts over a period of time  - using a Windows '95 program.....

4 hours ago, Paulkp said:

using a Windows '95 program

What's Windows 95 ? 🤣

I know I should not hijack the OP's topic, apologies Alastair, but for our colleague Uno from North of God's Country where they still use candles......

A brief history of Computing......

Memory was once in a ferrite core store, and could hold 16k of data, a program was loaded using an eight hole tape, start address was set by 16 switches, and it might run FORTRAN. Output to a teleprinter.....

Then we had laptops the size of a briefcase that needed two men to lift, Program disk (1.44Mb) went in drive A, and data disk (also 1.44MB) in drive B.  A keyboard for input, a small monochrome screen for a display, and it ran DOS programs.

All was well, until Bill Gates came along and ruined it !!

But you knew all that, didn't you !

 

 

1 hour ago, Paulkp said:

Memory was once in a ferrite core store, and could hold 16k of data, a program was loaded using an eight hole tape, start address was set by 16 switches, and it might run FORTRAN. Output to a teleprinter.....

Sounds a bit like the PDP-11s I used to use . . . . .

Early computers - don't get me going.  Paper tape into a computer that filled an old church.  Subsequent fun with George 3.

Returning to my current problem, I now have a UNI-T UT210E AC/DC clamp meter. Not yet convinced I am getting correct indoor AC current readings. Need a dry day to try it on the car! 

32 minutes ago, ASW said:

Not yet convinced I am getting correct indoor AC current readings.

Confused.com

I thought you were measuring the car.

40 minutes ago, ASW said:

Early computers - don't get me going.  Paper tape into a computer that filled an old church.  Subsequent fun with George 3.

Returning to my current problem, I now have a UNI-T UT210E AC/DC clamp meter. Not yet convinced I am getting correct indoor AC current readings. Need a dry day to try it on the car! 

You won't because you are measuring Twin and Earth cables. It will only work on AC if you separate the Live. 

Only extra hint I have (similar AC/DC clamp meter - invaluable https://www.amazon.co.uk/dp/B08PNTHS4C) is it may have a "relative" button to "zero" the clampmeter before placing on the car lead you are investigating?

Just now, Shearers said:

Only extra hint I have (similar AC/DC clamp meter - invaluable) is it may have a "relative" button to "zero" the clampmeter before placing on the car lead you are investigating?

There is a Zero Button and when you are under the Bonnet and near all the electricals it picks up all sort of things before you even open the Clamp.

With this one they recommend that you place it as near to what you want to clamp over then zero it then open the Jaws over the Wire.

The other thing I meant to say the other day was that it defaults onto AC even if you move the switch to another setting from memory.

Thanks to all for the advice.

Bad news, battery current data (as measured with a new UNI-T UT210E) appears to indicate that I do have a parasitic drain of about 0.25A.  Opened the bonnet and locked up, later returning without the key:

·       After 25min average reading 0.24A (range 0.19 to 0.33)

·       After 75min average reading 0.27A (range 0.10 to 0.35)

METHOD: Switch meter on, select 2A, SELECT DC, SELECT ZERO, clamp round battery cable then read.  Hard to set to ZERO at first but then held away (with same orientation) – presumably still picking up the current when close to the battery cable.

This suggests a maximum of ~10days for a fully charged 65Ah battery to run flat.  Also, street parked so not feasible to charge the battery.

Suggested next step?  No Ford Garage nearby but I have located an auto electrician (no information about him).

Focus 1.0L Manual Mk4 pre facelift (UK 69 Plate)

Make sure you lower bonnet enough as switch off any lights or alarm detection if it has any.  My old 2009 mk 2.5 I had to setup clamp meter then lower bonnet so it was sitting on locking catch or alarm was drawing amps(use a screwdriver to stop it fully closing over).

Next port of call, with your meter connected and bonnet down, have meter resting up on passenger wiper so you can see reading from inside car and after 25 minutes, start pulling fuses, 1 at a time.  When Amps drop, that fuse circuit's your area for further checking.

You can fool the car into thinking the Bonnet is closed by pushing the locking mechanism down with a screwdriver.

You do need to pull the unlocking handle again to open it before closing the Bonnet once you have finished though.

Thanks, I had understood that drain testing with the bonnet open was ok (if you wait).  However, I did notice that remoted locking the car after pulling the bonnet catch does cause a (warning) beep from the horn.  Will try the screwdriver trick and retest! 

Just an afterthought, if you've had anything fitted after getting car, front / rear dash cam hardwired, etc, I'd look at these first.

33 minutes ago, ASW said:

Thanks, I had understood that drain testing with the bonnet open was ok (if you wait).  However, I did notice that remoted locking the car after pulling the bonnet catch does cause a (warning) beep from the horn.  Will try the screwdriver trick and retest! 

Hello,

I always measured with open bonnet and locked car. I do not have any alarms nor any 3rd party accessories hooked up to the car. And with the bonnet open i have the drain of around 40mA (remember that the accuracy of that meter is at best within 10mA if the Zero has been done correctly).

Of course you can try the "fake" bonnect lock to see if there are any differences.

240-250mA is quite high drain. Does the car go into deep sleep mode? Normaly in this mode the ecus are forced to sleep and the drain should fall. If it doesn't, then there really is an issue somewhere. 

Diagnostic options:

1. start pulling fuses -> this will eventually disconnect the culprit from the eletrical network

2. measure voltage drop accross fuses -> this will not disconnect anything but it will give you an indication of current flow through each fuse and you can find which one it is.

3. After finding the fuse, find which ecus are powered via the fuse

4. This step depends on what you find at step 3.

 

Cheers!

Just measured the drawdown current again with the bonnet catch wedged, average reading of 0.33A after a 40min wait.  Suggests that if the bonnet catch detector was contributing, there is a much bigger cause.  I am not aware of any post build additions or modifications (other than normal SYNC updates) - but not had the car that long!   

Hi ASW,

So now that both bonnet open and bonnet "locked" resulted in rather high drain, it is time to start your fuse investigation:

1. open the door on the fuse side

2. use the boonet lock trick to "lock" the opened door

3. lock the entire car and measure the current until it settles to the drain value

4. start working yourself through each fuse. write down the pulled/measured fuse number and the current drain value. Could be several ECUs which are awake so you might have changes in the drain current of 50-100mA, not necessarily from 330mA all the way down to 40 mA.

5. After writing down everything you have checked, lookup the suspect fuse(s) and see what they are connected to.

6. Depends on what you find out on 5.

From these 330mA it looks like "most" of the car is sleeping. I base this argument on the drain i have on my car awake which is around 4 Amps and peaks at aroung 7 Amps when the ECUs are running some tests).

 

Other questions:

Does the car enter deep sleep? The Ford Pass app sends a notification when it does (asuming you have the app).

Do you have the possiblity of reading the DTCs? I once had a DTC related to the keyless entry sensors in the door handles. This never came up again, but i always wondered if that DTC might have ment the keyless entry does not let the door ECU to sleep. This happened in a period when i was constantly getting deep sleep notifications and the keyless entry was being deactivated on the passenger side.