Pulsing battery charge

Grumpy_chap

OK - so the battery on the Focus eventually gave up the ghost and I had a new battery in February.
Focus 2007, 1.6 petrol, zetec engine.

Apart from the display showing mileage never recovering, the car was OK after the new battery.

Been away for a couple of weeks and the battery is flat so currently on charge.  This should not be the case with a brand new battery - should easily last more than a couple of week.  So I guess that means there must be a parasitic load somewhere (which I sort of expected to be the case from before actually - it is just with a new battery that becomes more confirmed).  How do I find out what that is and how do I resolve it?

shiraz99

Grumpy_chap said:

OK - so the battery on the Focus eventually gave up the ghost and I had a new battery in February.
Focus 2007, 1.6 petrol, zetec engine.

Apart from the display showing mileage never recovering, the car was OK after the new battery.

Been away for a couple of weeks and the battery is flat so currently on charge.  This should not be the case with a brand new battery - should easily last more than a couple of week.  So I guess that means there must be a parasitic load somewhere (which I sort of expected to be the case from before actually - it is just with a new battery that becomes more confirmed).  How do I find out what that is and how do I resolve it?

Probably best to take it to an auto electrician. Things like this are notoriously difficult to track down without the right expertise.

Grumpy_chap

shiraz99 said:

Probably best to take it to an auto electrician. Things like this are notoriously difficult to track down without the right expertise.

Paying money will detract from my bangernomic success.

I was hoping that someone would say there is a common thing on the car and just unplug the XYZ fuse.

I am also frustrated that the mileage display LCD has died.  Seemed to go with the battery.

[Deleted User]

Grumpy_chap said:

shiraz99 said:

Probably best to take it to an auto electrician. Things like this are notoriously difficult to track down without the right expertise.

Paying money will detract from my bangernomic success.

I was hoping that someone would say there is a common thing on the car and just unplug the XYZ fuse.

I am also frustrated that the mileage display LCD has died.  Seemed to go with the battery.

Hop over to some Ford Focus forums and you'll find some suggestions, but the proper way to find out starts with using a multimeter to check the current draw from the battery during standby and then pulling various fuses to narrow down which circuit is doing the parasitic draw.

You don't have to try every fuse, a large number of circuits will be fully disabled once the ignition key is removed, so concentrate on those that remain live such as the radio, locking systems, alarm, interior lights etc

It is of course possible that the pulse charging that started this thread has knackered a component and the lesson there is always disconnect a battery before charging it - I do that even with my modern Ctek smart charger. The problem with the dashboard display suggests that could be fried and causing the problem.

Typical items on a Ford of that era that cause this are the alarm and the Bluetooth module. Any aftermarket components would be my first suspicion. On some models the alarm has a battery backup, possible that with the main battery being flat for so long that battery has died and is leaching current to recharge it without success.

My first look would be anything not working as expected - so the dashboard circuit.

facade

I have a vague recollection that the focus uses one of those "smart charge" alternators, and that the dashboard controls it somehow. I can't find anything useful on t'interweb quickly though, apart from a suggestion that the wire breaks close to the alternator where the loom is unsupported.

The idea of "smart charge" is the alternator runs full chat whilst the engine is warming up, because no-one cares about emissions at that time, then cuts back after the engine warms up so that it doesn't bother to charge the battery any more, reducing emissions when under test- hurrah for the planet!

I've no idea why the battery doesn't just go flat though- presumably when it gets to half charge the alternator cuts back in, a bit of bad luck if that is just as you pull up outside your house.

Grumpy_chap

I really need to move the car and park it on the road, so I have booked it in for an MOT on Thursday.  Once I have the MOT, I can get VED and park or use the car on the road.

Last MOT was Sept 2020 at 144,916 miles.
Last fill of fuel was Dec 2020 at 145,772 miles
Then we went into lockdown and I put the car on SORN at the end of December 2020

New battery in April this year (2022) but other than that I've only really turned the engine over periodically.  Checked all the fluid levels and all seem OK apart from coolant which seems to be going somewhere but I can't work out where.  Topped that up again yesterday.  Seems OK this morning.

So, the car should be an MOT pass, except the LCD display (like the green display in the pic below) has failed.  That means there is no display of vehicle mileage.  The other gauges seem to be working, though of course I can't check speedo on the driveway.



I just wondered whether no mileage display will be an MOT fail?  Can the garage get the mileage from the computer by plugging in a reader directly?

I don't really want to have to spend money on a new display.  In part because it will be wasted if there is something more substantial that needs fixing.  In part because the LCD display has been temperamental in the past and "cures" itself after a bit of a run so I was thinking that once I have an MOT, I can take the car out and see if the display self cures again.

facade

Grumpy_chap said:

I just wondered whether no mileage display will be an MOT fail?

No, the mileage is marked as unrecorded.  The speedo has to light up, and not be obviously broken (like stuck at 90mph or needle missing) They only check it is working if they road test it-  which would be if they can't check the brakes on the rollers due to 4wd.

Grumpy_chap

facade said:

No, the mileage is marked as unrecorded.  

That is good to know - thanks

I'm happy enough that the speedo will actually work and the fault is just the LCD display for total mileage (and the other stuff it can cycle through and display). 

It's also reasonably likely that the LCD display will sort itself as it has been temperamental before and a bit of a run to dry out any condensation / warm up the crystals has always done the trick.

Grumpy_chap

I just realised that my Focus has a full tank of petrol.
Rather than MOT and VED, I wonder whether I could sell it and retire on the proceeds

Grumpy_chap

Passed the MOT today
VED was £220
Almost a Bangernomics success...