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I last drove Rangie on 21st December and it worked flawlessly. Parked up as normal and then yesterday I came to drive it and the fob would not unlock it so I resorted to the key which unlocked the drivers door only, no central locking ‘unlock’. Key in ignition and absolutely nothing, nada, zip. The battery voltage was 1.7V!!! My less than one year old Hankook MF3-1000 battery is probably toast … sob.

Had to put on my very old traditional, unsophisticated battery charger to get it to take any charge whatsoever. Once it took a bit of charge it was put on life support ‘recovery’ mode of a more sophisticated and ‘intelligent’ C-Tek charger. It is now fully charged but is out of the vehicle and voltage showing good but no idea of capacity yet.

Fitted a back up battery I have that is kept charged and after overcoming the usual annoyance of the alarm going off all looked normal until trying to start the engine. Nothing, no click from any relay or solenoid. Hmmm! Decided to measure the current draw and with everything checked as being off it was draining at ~2A. The BeCM seemed to go to sleep correctly at the 2 minute mark but the drain then sat at a consistent 600mA!

I removed the starter motor relay (16) and bench checked it and all OK. Decided to short the relay contacts in the fuse box without ignition on to check stater motor and nothing, no power at the relay. Pulled fuse 40 and it was completely blown! Replaced fuse and shorted the relay again expecting trouble but the solenoid/starter motor span the engine over fine. Replaced the relay and she started fine, no warning lamps and alternator charging the battery fine. Shut down and restarted a few more times and all OK. Checked the battery drain again and all checked out with BeCM going to sleep and drain at ~30mA.

I can only think the starter solenoid threw a bit of a wobbly and after starting the car for the last time on 21st December then fried the fuse but managed to put the starter into a state where it was continually consuming current. Shorting the starter relay shook the solenoid back to its senses and all is now fine . . . but for how long?

Is my starter on the way out? What mechanism put the starter into a state where it was continually drawing ~1.5A? Is there any other explanation for this odd behaviour? Will my Hankook battery recover its masculinity? Answers on a postcard please!

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Hmm, a weird one. Looking at the diagram I can't see how the fuse blowing could cause a drain. A problem with the starter solenoid or starter relay could blow the fuse but once the fuse has blown, where is the power being drained coming from?

i suspect your Hankook will recover. There's an MF31-750 on the Ascot and that will go flat after about 4 or 5 weeks, which, as it is only used as and when we need two, is quite common. I stick the charger on it, put the EKA in, reset the windows and all is fine.

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1.7v is a bit like when a cat uses one of it's nine lives: one less to go, and just then it might find out that some of the other eight where already used...

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GARVIN: Don't think your Hankook is 'toast' just yet but one of its 6 lives may have shortened a little ?! Seriously it is probably best of course not to use an old/basic charger to raise the voltage like that (unless very briefly) before using your C-Tek... ( Don't know if yours has a 'Pulse/Repair/Desulphation' cycle facility but I have had success with that kind of unit in 'resurrecting' (almost) dead batteries - although eventually/usually a cell will weaken with many such cycles of course)

As for your drain itself (in my case/P38) after some weeks this can happen - and I have assumed, particularly in winter, that it is probably caused by a combination of condensation/muck/road salt somewhere (!) Not very helpful I know but I fitted a small LED voltmeter on the dash a while ago to keep an eye on things... Much cheaper than a(nother) new battery !

( Before someone comments I eliminated the usual alarm/EAS/BECM drain 'culprits' years ago too )

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davew wrote:

As for your drain itself (in my case/P38) after some weeks this can happen - and I have assumed, particularly in winter, that it is probably caused by a combination of condensation/muck/road salt somewhere (!) Not very helpful I know but I fitted a small LED voltmeter on the dash a while ago to keep an eye on things... Much cheaper than a(nother) new battery !

( Before someone comments I eliminated the usual alarm/EAS/BECM drain 'culprits' years ago too )

In the case of my Ascot, and probably most others where a car is left not being used, it is likely down to a combination of multiple things. First there is the 25-30mA draw that the alarm and other permanently powered items cause but as well as the EAS waking up every 6 hours or so, as it still has the original first generation receiver the BeCM will wake up for 2 minutes every time I lock or unlock my car or the missus locks or unlocks hers. Under the circumstances, I don't think 4-5 weeks is too bad. A voltmeter wouldn't be a lot of help as that would involve checking it and the only time the Ascot gets looked at is when I know it is going to be used. If the battery is flat at that time I'll either stick the charger on it for a few hours or, if I need to use it urgently, jump start it off one of the others. I've thought about putting a solar trickle charger on it but the only real advantage of that would be to save me having to enter the EKA, reset the windows and sunroof and, most annoyingly, guess how much LPG it still has left in it as the trip meter will have dropped to 0.0 so I've no idea how far it has been driven since it was last filled!

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Thanks for the replies.

I put the Hankook on the C-Tek but it just didn't register a battery was there the voltage was so low so it was put on the old charger briefly, just to get it to a voltage where the C-Tek could take over on its specific repair/recovery programme. It's now been moved from ICU to a recovery ward where its voltage retention will be measured before 'discharge' (pun intended) and refitted to the vehicle and put back to work. Time will tell if it was young and strong enough to make full recovery but I've never had a battery recover from such a deep discharge before but they had all been batteries that had been in service for many a year..

What could blow fuse 40 is a good question - only the starter solenoid, EAS compressor and diaphragm valve are powered from it. However, with the fuse blown any continual drain from these items is impossible! I even checked relay 20 to see if it might be stuck on but it checked out OK. Besides which the compressor still seems to be working now, however I will keep an eye on it just in case it is getting a bit ropey (I have a spare reconditioned compressor on the shelf as well). The only thing that is associated with fuse 40 and is permanently connected to the battery is the starter motor itself which is why I am being drawn to it being the culprit - I'm not entirely au fait with its internal workings but I have refurbished a couple of other vehicle starters in the past and can see, despite how unlikely, a solenoid might be kept engaged for a prolonged period of time by the main cog engagement mechanism which might explain the the contacts in the motor/solenoid being connected and drawing current until the fuse just plain overheated and blew. If the main cog stayed somewhat engaged the contacts of the motor may only be lightly engaged leading to not enough current to spin the engine but enough to draw a current. Far fetched - probably but I can't see any other plausible explanation for the current draw.

The only other possibility I can think of is that the current drain is a coincidental and started and ceased at the same time as fuse 40 blew. That seems even more unlikely though.

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Richard: The LED Voltmeter is permanently on, visible from outside, and I use this same approach on numerous vehicles (either via the cigar lighter socket or the OBD connector). Particularly handy when these drains happen - apparently at random, à la p38 of course ! Over the years (on other cars) I have often found the most common problem is damp in the fuse-box, notably those that have the PCB-type multiple interconnect layers....

Garvin: I like your 'deductions' there - a partly-jammed/engaged solenoid might do all that (but, depending on the exact nature of the limited contact and current to the motor. it would probably discharge it rapidly (?) Guess you will have to pull the relay/fuse and put the car in the observation ward for further investigations ?!

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From a dealer perspective, when these cars were new, 6 weeks was seen as the maximum time that you could go and still have power to start. That is new truck and new battery. Second hand cars 4 weeks.

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Marshall8hp wrote:

From a dealer perspective, when these cars were new, 6 weeks was seen as the maximum time that you could go and still have power to start. That is new truck and new battery. Second hand cars 4 weeks.

Frankly I would be amazed if they could manage 6 weeks in a dealers forecourt thanks to their (original) famous/hopeless 'oversensitive' Alarm/Rcvr. issue !

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Interesting thread - starter motor failing to disengage is very plausible... As regards leaving these cars standing for any period of time...it takes less than a minute to pop the hood, remove the negative off the battery and slam lock the doors

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Mystery solved or the main bit anyway!

Went out earlier to check battery for drain - none apparent. Fired up on first twist of the key and ran happily. EAS very sluggish, so went under the bonnet to witness the EAS compressor struggling somewhat. It then cut out without the pressure switch operating and, on taking off the housing lid, was close to spontaneous combustion having run for only a minute or so! The fuse 40 blowing culprit at last - seems to be seized and not sure whether it just expired or the thermal cut out stopped the action! Took some time to get it out because it was so damn hot! Anyway, spare compressor in and everything back to normal . . . until the next P38 'surprise'!

Can't explain the excessive drain measured, don't think I had a door open or whatever the first time, but it's no longer present.

Battery going flat - I can only assume that because I used it for a few short journey early in December and used the 'Prog' button extensively to defrost/de-ice everything - I did use it a couple of times in succession which was a bit naughty - the alternator output was left funding the heated screens and blowers outrageous thirst plus the lights and not re-charging the battery after the start ups. Left for those few weeks during the coldest weather without much charging and the battery must have slowly, but inexorably, discharged.

Hankook is holding onto the charge so far. I will swap it back in after a few more days if the charge holds up and, fingers crossed, it is is none the worse for its excessive efforts in December.

I have also apologised to the starter motor for besmirching its reputation!

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romanrob wrote:

As regards leaving these cars standing for any period of time...it takes less than a minute to pop the hood, remove the negative off the battery and slam lock the doors

There is a way of doing it if you don't mind a bit of faffing around. Open the bonnet, close all doors and tailgate and lock with the key (not with the remote). Disconnect battery negative and close the bonnet. When you want to reconnected it, unlock with the key, open bonnet, close the door and lock again with the key, reconnect the battery and unlock with the key before closing the bonnet. That way when you reconnect it, the car is in exactly the same state as it was when you disconnected it, doors all closed but bonnet open and locked with the key. I've done this on a couple of cars and the remote had stayed in sync, the windows had stayed set, EKA wasn't asked for but the radio had lost the stored stations. However, I can't be bothered to do that on the Ascot, if I go to it and find the battery has gone flat then I know I left it for too long.....

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I'm not patient enough, but good to know :o)

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Final instalment, I hope.

Hankook holding charge and nice green glow in the peep hole so decided to swap it back in. However, still intrigued by the drain/no drain I decided to run the test by the book. Ammeter connected in series with the negative battery line. Open the drivers door and interior lights come on. Close door and current running at just over 3A until interior lights extinguish then current drops but jumps about between ~1.6A & ~2A and a number of readings in between changing every 1/2 second or so. Two minutes in the current drops to a steady 570mA. At just over 3 minutes the current drops to 35mA as the BeCM finally goes to sleep.

It seems I initially read the reduction to 570mA as the BeCM going to sleep at 2 minutes whereas it seems to finally go to sleep at over 3 minutes. I was confused as when I initially ran the test as I came back just after 2 mins, saw a steady 570mA for 30 seconds or so and thought I had a drain. On subsequent testing I came back after over 3 mins and saw the 35mA so thought the drain had miraculously cured itself! Only when continually watching it today did I see it progressively step down to the final sleep current draw.

No long term abnormal drain but does anyone know why a) the current jumps around before 2 minutes; b) what the steady 570mA draw is; and c) is this step down normal? Reading the formal Iq test it just states for the current to reduce to ~30mA in 2-3 minutes after interior lights extinguish. Well mine takes about 3mins 15 secs!

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You have something drawing around 535mA for 3 minutes but not continually but on and off every 1/2 second or so. That would suggest a flashing light or similar. With interior lights on, you've got 3A draw, lights go out and it drops 1.6A but with the mysterious flashing making it jump between 1.6 and 2.0A (or thereabouts) until the BeCM goes to sleep so it drops to 35mA but the flashing has now become a permanent 535mA draw until it switches off after a further minute. The only thing I can think of is the alarm system with it's flashing LED on top of the dash but that normally sorts itself out before the BeCM goes to sleep and wouldn't be enabled if all you did was shut the door and not lock it.

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When the interior lights go out the current draw drops from over 3A and then ‘wangs’ about at various values between 1.6A & 2A. If it was a flashing light or similar I would expect it to jump up and down consistently between two values but it doesn’t, it seems to be all over the place. When all this stops at the 2 minute mark the 570mA holds rock steady for the final minute or so before it finally drops to the 35mA. It’s not the alarm LED.

It’s strange to be sure and I can’t think what circuit would be ‘live’ for two minutes with a varying current. I assume the steady 570mA is the BeCM and the actual ‘wanging’ about is something varying between ~1A and ~1.4A on top but I can’t think of anything that would do this and then shut off after 2 mins. EAS perhaps? I think will have to just go through pulling each fuse in turn until I find which circuit is responsible but I only have a short time to pull/replace fuses one at a time so it may take some time to get through all of them! First though, I might try locking it after closing the door and see if that makes any difference to the current draws before the BeCM has its kip!

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Interesting... and the EAS can certainly be 'active' like that once you have locked the car - if/as it levels up but the 'click/clack' from its valve block is the real 'giveaway' for that if so... (?) Not meant to be a 'daft' question but are you actually closing the bonnet whilst reading these currents (as that might also upset things, notably the alarm) too ?

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Yes, bonnet was closed with ammeter on top of bonnet. However, bonnet open or closed doesn't make any difference and there is no 'open bonnet' warning ever displayed and the car will lock quite happily and set the alarm with the bonnet open and no 'chirp' from the alarm sounder as it will for any of the doors. It's always been like this since I have had it!

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That's also odd of - course - is the bonnet switch maybe shorted ? Guess your EAS will still work with it open too ?

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I assume the bonnet switch is attached to one of the catches on the slam panel. I’ve had the slam panel off many times but never had to disconnect any electrical wires (or noticed any dangling about under it)! As for the EAS operating, I’ve never noticed but, then again haven’t had the bonnet open and the vehicle locked on many occasions (or driven it with the bonnet open)!