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PaulRandell

2002 Petrol Mondeo - Faulty Alternator? - Battery Drain

53 posts in this topic

i would forget about pulling fuses for now...there is a problem with the battery itself at the moment.

11.7v after being left disconnected overnight is a flat battery...slightly lower, maybe 0.5v, and the car wouldnt have started..its actually taken a 5 mile run to get the battery to read above 12v, and at 12.06v is still very low charge

imagine the battery was connected overnight, soon as it drops below 12v, then its quite plausible the alarm will mistake this for a voltage drop, such as a door being opened, it may or may not have triggered the alarm, but it may increase the drain as it tries to deal with the info...not saying this is whats happening, but its one of a number of possibles

the battery will also struggle to maintain a charge at that voltage with a normal amp drainage.

first step has to be, charging the battery to an acceptable level...get it to at least 12.3v after charging and left for couple of hours.

from there, i would personally leave it disconnected overnight before taking another reading..any drop in voltage more than 0.2v i would suspect a battery fault..even 0.2 is pushing it, ideally you will want to see less than 0.1v difference

if battery has sustained an acceptable voltage, then you can carry out the drain test and get a truer reading...11.7-12.06v is way too low

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I purchased two batteries in Jan 2014, one for my mondeo and one for my wifes mondeo.

My battery is at 11.86v and my wifes is 12.37v, my battery is on charge and I will check the voltage tonight and then compare any drops in voltage on both tomorrow morning.

I'll leave the fuse pulling until as you suggest my battery is at an acceptable level. I am assuming that this issue has had a negative effect on the battery.

In hindsight I wish I had paid more attention to the voltage of the battery before.

Thanks for your help

Paul

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Ok last night my battery after 4 hours of charge 11.30pm 12.76v 9.05am 12.68v

One 0.5m journey this morning battery now 12.51v

I have had one reading on my meter of 3.61a all morning, in that time I checked all the relays and all the fuses in the fusebox and no change to the drain, even F30 and R5 ??

I can't get either of the connectors off the back of the alternator, where would I find the the bat+ connection?

The only fuses/relays I didn't get the chance to check were F11 F20 F21 F13 F15 F24 R1 R3 R2 R4

I will keep trying, not sure if I have isolated the alternator yet or not?

Paul

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are you saying that this morning you had a constant 3a drain or just a short time of 3a..if just a short time, when did it appear and for how long?

also, are you saying you have eliminated all the fuses in the fascia fusebox and most of the fuses in the engine bay, bar those you listed?

the BAT+ is the thick cable to the rear of the alternator...probably red in colour..if you cant access it, then might find the red thick cable to the back of the starter easier to remove, which will also isolate the alternator.

the battery cable goes from battery to starter to alternator

you will also need to remove fuse 30, that way the alternator is totally isolated from the battery, so if you still pick up a 3a drain with everything switched off, then you will have eliminated the alternator as a suspect

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After approx 4 hours of testing I had approx 4 minutes of finding the 3.61a drain and another 4 minutes of a 3.30a drain, in that time I checked most of the fuses in the engine bay, but none of the fuses in the glovebox.

I stated trying to replicate the drain (open doors, put on lights etc) but nothing really worked. I started thinking that it only drained in low temp? or that it was something to do with the central locking as each time I touch the battery in line with my amp meter the locks click. Or that it is something that switches off/on after 20 minutes of no activity?

I have also searched on the internet and there are a few instances of the battery saving relay failing and causing a drain?

Pretty frustrating really, is something like this going to help?

http://www.ebay.co.uk/itm/Ford-Mondeo-OBD2-Fault-Code-Reader-Reset-Tool-1997-onwards-/171174693645?pt=UK_Diagnostic_Tools_Equipment&hash=item27dace8b0d

I am pretty much committed to Mondeo's so something like this may well be an ongoing investment (looks a bit cheap but may help?)

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Small update.

This morning I checked the battery, it was drawing 3.47a. My son kept the meter on the battery, and I started removing fuses and relays from the glove box.

First was the battery saving relay - No Change.

I got to F66 and the draw went from 3.47a to 0.84a not ideal but I did have the passenger side door open.

I am pretty sure that whatever the drain is, it starts approx 1 hour after leaving the car and is then permanently on. As soon as I connected the meter this morning it was at 3.47a.

If that is the case then at least I know how to ensure the draw will be high when I return to the vehicle, which will make the drain test on the glovebox fuses much easier/quicker.

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i doubt it on this occasion, that will only pick up engine fault codes, which unlikely to have occured with your fault beyond a possible battery out of expected range type code.

though tool can be useful otherwise

wouldnt be concerned with locks operating when connecting amp, this isnt unusual, your more interested in current drain after everything has settled

not aware of a battery saving relay, so may pay to find which one they are referring to and make a note of removing it when drain appears

can understand the frustration with an intermitent problem like this, , just keep disconnecting the battery when not in use, keep an eye on that battery voltage, keep it at a good charged rate...

beyond that there isnt much you can do to speed up finding the fault...but just think of the money your saving by doing it yourself, not aware of any equipment available for specialists to pin the problem down faster so your saving a good few hours of labour rates not to mention if it turns out not to be alternator, youve saved on the cost of that too.

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This morning I checked the battery, it was drawing 3.47a. My son kept the meter on the battery, and I started removing fuses and relays from the glove box.

First was the battery saving relay - No Change.

I got to F66 and the draw went from 3.47a to 0.84a not ideal but I did have the passenger side door open.

With the passenger side door open, presumably (unless disabled by a removed fuse) you have the interior courtesy lights on, So, again presumably, most of the 0.84 A would go away with the door closed. So far, so good...

Obviously, if anyone actually knows what F66 does, that would be ideal. (There is an obvious question about whether you could run with F66 removed, temporarily - it it is lighting, you couldn't, but it could be a convenience function that you could live without, for a short time).

I am pretty sure that whatever the drain is, it starts approx 1 hour after leaving the car and is then permanently on. As soon as I connected the meter this morning it was at 3.47a.

I can't think what is likely to kick in 1 hour after hitting the lock button (I assume that its that, rather than, eg, the ECU doing something odd 1 hr after the ignition switches off - in some cases there is a 'power hold relay' for the ECU so that it gets time to tidy up after running, but that tends to be in the multiple seconds to one or two minutes range, rather than an hour).

Err, yes I can think of a 1 hour thingy, sort of. The radio head unit tends to get one hour that it will stay on until it auto-powers-off. Now, that's one hour before the power kicks to off, not on, but maybe there is a signal to a relay, or something...

Please check any and all wiring associated with the radio to check that there isn't something which could short to ground or an adjacent wire and which could be involved in a current draw. Look carefully at insulation to check that hasn't lost its integrity allowing a short. If in doubt, and there are unused wires floating about (or connectors with exposed pins), use a rubber band to secure a plastic bag over them, for the moment.

Edit:

The other 1 hr thingy, that I could think of was the engine/radiator cooling fan; normally it will run for a period after the engine has been on, and, if the temperature is high. I imagine that they cut the supply to the fan after a period to ensure that a sensor failure doesn't leave the fan running 'for ever'. That period might be one hour...and if the ECU drives the fan, the ECU is probably on for an hour, after the engine has run.

Edited by BOF

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F66 is (apparently) the driver's seat motor.

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i read his last post as current drain dropped to 0.8a before removing F66....but he also stated currnt drain appears permanent after 1hour...so bit confusing

if i read it wrong and F66 stops the drain, then drivers seat has to be the area to look for wiring problem

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The draw reduced from 3.47a to .84a when i removed F66.

F66 is still in, and I am driving as normal but disconnecting the battery each day at work and each night at home.

I have disconnected the radio and checked the wiring, everything seems ok, and it made no difference. I am pretty sure it is not the radio.

Some slightly more worrying news, I drove 20 miles to work, stopped at a garage for petrol, went in to pay and when I came out all the windows were down, nb: I didn't lock the car. (never seen this before)

Starting to worry that my small electrical problem is becoming something bigger.

Hopefully I will be able to test some more tomorrow am.

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The draw reduced from 3.47a to .84a when i removed F66.

F66 is still in, and I am driving as normal but disconnecting the battery each day at work and each night at home.

Would removing F66 be easier/quicker and does that do the job?

Some slightly more worrying news, I drove 20 miles to work, stopped at a garage for petrol, went in to pay and when I came out all the windows were down, nb: I didn't lock the car. (never seen this before)

Starting to worry that my small electrical problem is becoming something bigger.

Are the windows on a separate fuse (from F66)? The windows and the seat will probably be on the same module, if not the same fuse, so that might be pointing somewhere.

Just as a re-cap, am I right to conclude that with disconnecting the battery overnight/during the day, the battery seems to be charging absolutely normally now?

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went in to pay and when I came out all the windows were down
Sounds like you have global opening/closing on your car. If you hold down the unlock button for about two seconds, all the doors will unlock and all the windows will open. Likewise, if you hold the lock button for two seconds, all the doors will lock and the windows will close (note, the windows probably won't close if you've had the battery off).

Is it possible you could have accidentally held the unlock button down at some point?

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The battery is charging properly, and maintaining approx 12.5v

I could of held the button down too long but i am pretty sure I didn't as I didn't lock the car at all, since then I have tried to use the global opening/closing function, but it wont work!

My plan is to remove F66 and see if I can replicate the drain.

However, in the meantime I have had my wifes Mondeo MOT'd (passed with just an adjustment to the handbrake/pads :) ) Different garage to the one i took my mondeo to earlier this month. I spoke to the guy there and explained what the problem was with my car, and he was sure it was an earth strap issue.

Either from the battery to the gearbox, or from the gearbox to the bodywork, he suggested I clean everything and double check the connections and cables before doing anything else. I am going to give this a try on Saturday morning, is there any test to confirm an earth is working?

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bad earths will not cause a battery drain, they will cause charging issues or powering issues...but they wont drain your battery overnight

but if you want to test the earths you can do a simple voltage drop test

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Ok, finally some progress.

I double / treble checked and cleaned all the earths I could find, but especially the gearbox earth strap.

I then went to continue the drain test, it immediately went to 3.9a (highest reading so far) and the was a buzzing noise coming from the steering column.

I have checked and double checked and the problem is with the indicators! Fuse F25 (15a) removed takes the draw from 3.9a to 0.5a.

It remains at 0.5a, the buzzing stops, but the indicators now make a sound as if the are going (but they aren't illuminated) which I guess is accounts for the 0.5a.

So that is the good news, the bad news is I now have no idea what to do!

Any suggestions would really be appreciated.

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I have checked and double checked and the problem is with the indicators! Fuse F25 (15a) removed takes the draw from 3.9a to 0.5a.

It remains at 0.5a, the buzzing stops, but the indicators now make a sound as if the are going (but they aren't illuminated) which I guess is accounts for the 0.5a.

You mention a 'buzzing'; there should be a relay that clicks on and off. In either case, check any relay that is either buzzing or clicking and check that there isn't corrosion on the connections. You may or may not be able to have a look inside, at the actual contacts. This relay should be fairly easy to find, as it probably nestling in a fuse box somewhere, and probably plugs in.

The other thing is that there will be a module that drives the relay (or, maybe, it drives the indicators directly) and if there is a problem with earths, it is more likely that the earth to that module that is in poor condition....then the module malfunctions, and all sorts of odd things can happen.

Outside of this fault (that is, outside of the condition with the car essentially switched off, and the current drain varying) do the indicators work normally, or are they dim or switching at the wrong speed (and that includes what happens when you lock/unlock the car)?

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The buzzing is definitely coming from the steering column (indicator stalk), no noise from either fuse box at all.

The indicators work perfectly, and they come on when I unlock and lock the car.

I have looked into F25 and it is actually the Central Timer Module that may also be the indicators.

I followed a test/reset option as per another post on this website

http://www.talkford.com/topic/202236-central-timer-module/

It beeped and I tested both stalks and everything seemed to test ok, I turned the ignition on and off and it beeped 4 times.

Sadly I can still find the drain, still it is another item ticked off the list. I cant seem to locate any relays for indicators in either fuse box.

Is it likely that as I can hear the buzzing in the steering column that the relay is in there?

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f25 is the multifunction control module, which is situated in the dash below the steering wheel..

the indicator relay is built into this module...it also controls a number of other electrics including alarm/central locking/indicators/few warning lamps/sirens such as alternator/lights on/door open....and a whole lot more beside.

if that module is causing problems, then it may take more than one fuse to pull that current draw down to the required level as a number of circuits run through it..

the obvious next test to make is unplug the module and check your drain again

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should add that diagnosing a faulty module will be very difficult, so even if the draw drops to an acceptable current, you may find the problem actually lies elsewhere, bearing in mind that a number of circuits run through it.

as an example and something worth checking for...lets say there are broken wires in the loom where it leads into the doors...they are broken/shorting across..those wires will include, alarm (so therefore includes indicators) windows, central locking...you now have a possible explanation for widow opening, alarm issues, indicator issues and an f25 fuse removal making a difference to drain...

unfortunately, havent got a wiring diagram that will help link f66 to this, but i know seat belt warning is part of control module, so may well be a link

if it was me, i would check the loom on all the door openings, especially the ones in common use such as drivers door and tailgate...you just might find your problem with any luck

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I have found the multifunction control module, I started removing all 5 connectors in turn and no difference to the drain.

I have looked again at the power seat adjustment, and when everything is off (key out) the power seat still works, and when I press the button the interior light goes on and off.

I disconnected the seat completely and there was no difference to the drain.

I disconnected the interior light and no difference to the drain

The only other thing I have noticed is that someone has removed both the footwell bulbs.

I also tried disconnecting every connector under under the steering column I could find in turn and there was no difference to the drain.

Is it possible that the modification that a previous owner did to turn off the seatbelt warning is an issue? Does anyone know how to reverse that modification?

The only other thing is that the drain varies between 3.5a & 3.9a, if the drain isn't present it goes back to 0.02a, if I open a door the drain is 0.84a, but I have never seen a drain of between 4.34a -.4.74a (ie: both the drain and an open door) which I guess means it is something to do with the central locking?

Of course I am now thinking of about 100 different possibilities, and I am not sure I have eliminated anything yet.

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can you confirm you had, at one point anyway, completely disconnected the mulifunction module, or as your post suggests, only disconnected one, checked drain, refitted and pulled the next one....

taking it for granted that it was completely disconnected at some point and drain was still 3+A, then bearing in mind the fuses you pulled made a difference, then think your next step HAS to be isolating the alternator (multi function module includes alternator warning light)...this was the area pointed out to you by the garage, only way of confirming if they are right or wrong is to isolate it...

if that fails to make any difference, then it has to be worth pulling the rubber boot back and checking those wires as they go through the drivers door...a lot of the wires in there will be related to the strange issues youve noticed (such as windows open)

only saying drivers door as this is the door that sees a lot of opening/closing so therefore at a higher risk of wiring damage...could also be any of the other openings too, particularly any that see fairly regular use

if you do that and still show a drain, then i would redo all the fuse checks in one go, making sure doors are closed and everything off...when doing the interior fuse, remove the fuse that controls the interior lights if you cant check without door being open....you need to get a definitive answer to what and how many fuses make a difference..make a note of all the changes.

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Ok.

I have disconnected the alternator, no drain tested it for the last hour or so, no drain.

Reconnected the alternator and drain re-appears.

Battery now 12.07v and 13.21v at idle which I guess means the garage was right in the first place.

Is this my best option, I have seen some on ebay for £30 but I guess I am asking for trouble with those.

http://www.eurocarparts.com/ecp/c/Ford_Mondeo_2.0_2001/p/car-parts/car-electrics-and-car-lighting/electrical/alternator/?401590702&1&3223abeeab311ec68527eb17b6052a50e897afcb&000012

How much should pay to get it fitted?

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U should do it yourself don't even need a jack 15 spanner for tensioner a ratchet 13 and 10 socket all access from top of engine

Sent from my iPhone using Ford OC

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U should do it yourself don't even need a jack 15 spanner for tensioner a ratchet 13 and 10 socket all access from top of engine
If I could just expand on this a little, because it isn't as straightforward as that.

First off, you'll have to remove the auxiliary belt which is under tension - you need a special tool to release the tension (Sealey VSE5944).

Second, there are bolts you need to remove on the bottom of the alternator. I would not even attempt to do that from above - it will be at best, extremely difficult. Aside from the fact that the alternator is a very bulky part, and removing it from the engine bay will be a combination of twisting/pulling/swearing. It's a lot easier to remove the wheel and wheel arch liner to get good access from the side/below. Also, doing this will give you much better access to the pulleys - if the belt happens to come off one of them (which is likely when it isn't under tension), you'll otherwise have a pig of a job getting it back on correctly. I would also suggest that while you're in there, you inspect the auxiliary belt too - if there are excessive cracks across the belt ribs then I would replace it. You do need to take off the alternator mounting bracket and belt tensioner to remove it, but since you'll be half way there anyway it could be worth it for the sake of an extra tenner for the belt.

When you refit the auxiliary belt, check, double-check and triple-check that it's routed correctly and is seated properly around all of the pulleys.

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