Auto Electrics

[Octopus]

Ok, anyone got any ideas about the following "car" problem.

Last week, on our family holiday our trusty Ford S-Max refused to start, so I called the AA and they took it to a Ford dealer to "unlock" the immobiliser, test and they fitted a new battery. Just left it for about 62 hours and its very flat again.

No lights left on, no accessories left on.

Me thinks that something is being left on, but what?

I'm VERY reluctant to put it in the garage at £89/hour to let them "look" at it.

The father in law has a friend who had a similar issue and it was tracked to faulty towbar electrics connections ..... our has a towbar to I'm going to take a look at that.

Have any members experienced anything similar??

Any ideas??

Thanks

Yours frustrated...

 

[Strima]

Dodgy battery, it has been known for new ones to fail. Also if an alternator is on it's way out the battery can discharge through it.

Try pulling out the glove box lamp.

The long winded trick is to disconnect the positive lead then link through with a multimeter, just don't try to start it... :lol: Pull fuses until the meter shows a significant change to narrow down the circuit. Vehicle electrics used to be simple but too many gadgets now and it's not as if you can IR the thing.

 

[Octopus]

The AA man who came to our rescur did test the battery and the charge off the alternator, so maybe those are OK.

Like the idea of removing the glovebox bulb as a first step!

 

[alli]

I've heard blown bulbs can cause battery discharge if when they blow the element melts straight onto the neutral

A mate had the same problem, which if I remember correctly was finally tracked down to a metal washer in the cigarette lighter

Probably not it, but worth a look as it easy to do

 

[UNG]

Just Googled "ford s max battery drain" this seems to be a common problem but without a definite and clear solution

To be honest while some of the traditional methods of fault finding may work without access to the right diagnostic software or equipment you may be in for the long haul as so many systems on vehicles these days are interconnected making it difficult to narrow down the actual fault

From reading other vehicle forums due to the amount of electrical and electronic systems on cars these days alternator and battery failure is a common problem also batteries tend to be lead calcium or silver calcium rather than the more common lead acid so making sure you have the correct replacement battery is essential

 

[Octopus]

Just Googled "ford s max battery drain" this seems to be a common problem but without a definite and clear solution

To be honest while some of the traditional methods of fault finding may work without access to the right diagnostic software or equipment you may be in for the long haul as so many systems on vehicles these days are interconnected making it difficult to narrow down the actual fault

From reading other vehicle forums due to the amount of electrical and electronic systems on cars these days alternator and battery failure is a common problem also batteries tend to be lead calcium or silver calcium rather than the more common lead acid so making sure you have the correct replacement battery is essential

Good input - thanks.

Ford in France fitted the new "Ford" battery so I'd like to think it is the right one!

 

[ruston]

Similar to Strima's post but use your clamp meter if you have dc on it. If it's a diesel check the glow plugs are switching off , and all the other things previously mentioned.

Start you car up and load the alternator up with all the heavy loads and see if it produces over 12 volts , 13.8 is nice at start up reducing to around 12 as it recharges. As said masses of electrics to go wrong , but Check the alternator belt for tightness,
and the plug into the alternator if it has one . May be something simple.

As well as glove box check the boot light and the interiors , you may not have noticed them on in long daylight hours.

 

[DNS1]

The long winded trick is to disconnect the positive lead then link through with a multimeter, just don't try to start it... :lol: Pull fuses until the meter shows a significant change to narrow down the circuit. Vehicle electrics used to be simple but too many gadgets now and it's not as if you can IR the thing.

I was going to suggest the same thing (but I agree with the "don't start it" bit! I fried a multi a few years ago like that!)

If you have no luck, look for an independent auto-electrician. A lot of them will do a few quick diagnostics for free for you.

Had this a few years ago with my old Vauxhall Vectra. Battery kept losing charge overnight... I tried everything except the alternator which was new. In the end an auto electrician spent 2 minutes with it and told me my new alternator was faulty and draining the battery itself.

 

[UNG]

Start you car up and load the alternator up with all the heavy loads and see if it produces over 12 volts , 13.8 is nice at start up reducing to around 12 as it recharges. As said masses of electrics to go wrong , but Check the alternator belt for tightness,
and the plug into the alternator if it has one . May be something simple.

The calcium type batteries need a higher voltage to charge than the lead acid types alternator outputs are typically 14v - 15.5 v. If you using a battery charger you need to check it is suitable for calcium batteries

 

[ruston]

The calcium type batteries need a higher voltage to charge than the lead acid types alternator outputs are typically 14v - 15.5 v. If you using a battery charger you need to check it is suitable for calcium batteries

Been out of vehicle electrics for a long time now , when did the calcium batteries come in ?

Disregard that lol i knew them as them Hybrids.

 

[cloverman]

Faulty rear windscreen heated demisters use to be quite common for causing battery drain !

 

[drew35]

You first need to measure the amount of "quiescent current drain". To do this connect an ammeter in series with the battery cable, you must then shut the bonnet, or trick it by taping the button down or flicking the latch. Then leave the door open nearest the fusebox, but close the door latch with a screw driver. Then set the alarm and watch the current draw drop, some vehicles take as long as 60 minutes to go fully to sleep. You really need to get the drain down to around 0.03 amps, or the lower the better. If you're killing the battery in a few days your probably still drawing in excess of one amp.

Don't worry about interior lights the vehicle will kill them itself if they're left on. It could be something as simple as a relay coil holding on, to a faulty ECU, water ingress into electrics, water in tow bar electrics, radio, smart fuse boxes etc, the list is endless.

You can try and narrow it down after getting the vehicle to "sleep", start taking fuses out one at a time and checking the drain, but you must replace the fuse before removing the next. The only problem is certain fuses being removed will "wake" the car back up causing the drain to rocket, then you need to let it get back to "sleep" again. You can try pulling relays also, but some relays and fuses will be hidden and not in the main fusebox. Chances are you could have more than one fuse box also, rear, middle, and under bonnet.

 

[Brightspark2]

Could be the alarm...

Try the multi meter method or if not get it too a good local garage rather than ford...I'm guessing your back from France there...

Sent from my Xperia S using next doors WIFI.

 

[ruston]

Just a thought . Check on the Ford site for recalls , If it is a common problem and you did not buy the car new they may of not tracked you down yet. Worth a try and could save you a few quid and some hassle.

 

[MarkieSparkie]

Common causes of battery draining on the S-Max are software bugs causing modules to stay awake instead of shutting down. The S-max is fitted with 30 + complex modules and the battery drain could lie anywhere among the variety of modules.

Carry out a battery drain test (vehicle locked and bonnet latch closed down) with an ammeter after 1 hour you should have a reading of less than 0.05 amps. If there is a drain then further diagnosis is required to identify the awake module.

Known issues with the firmware of ABS, Immobiliser, alarm, BCMII, PCM, audio and Bluetooth modules. So the first step should be to have all the vehicle modules firmware updated to the latest specification, then repeat battery drain test before further diagnosis attempted.

Deteriorating headlight switches and/or corroded connectors also known to cause similar symptoms.

The alarm horn unit, mounted behind the passenger front wheel arch, is known to suffer from water ingress, particularly on early models, later models are generally better sealed but not always.