Sudden Death

[KARL]

If there is anyone with good knowledge of car mechanics, or in fact particularly electrics, I would be grateful for advice.

This evening we left for a dinner appointment in our 1990 Golf2. The car has just been taken back into use after six months of standing still, resuscitation was easy and we have been using it since the past weekend. Within a short distance from home, after a single stutter it abruptly stopped stone dead. There is plenty of fuel in it and the battery is good. Yet there is no power for starting at all, as if the battery has in this matter of minutes been completely drawn down - there is not even sufficient power to operate the central locking, but the charge (not charging) light comes on.

What is the likeliest cause of this ? I am wondering whether the alternator might have failed, but I have to admit this is a complete mystery to me. It will not be until the morning that I will begin to have a look at things and no doubt involve someone else.

[bhg481]

You say the battery is good - why do you say that if it won't operate the central locking? How old is it? Have you kept it charged whilst the car was not in use?
It's a fairly old car that hasn't been used for 6 months; any chance the cam belt has snapped?

[KARL]

The cam belt was replaced fairly recently, a broken cam belt would not completely kill the electrics. The battery is effectively new, it started the car fine just minutes earlier. Anyone posting comments/advice please base these on the description.

[tonyav]

Check the earth straps, battery to body and engine or gearbox to body. unbolt them and clean up ( bit of emery clothe will do )both ends of the straps.

[ToraToraTora]

charge the battery, if it goes flat again it's the alternator. You can verify this with a multimetre. Whilst runing put the prongs on each terminal, if the reading is less than 12, the alternator is knackered. Ideally it should be around 14.

[bhg481]

I can't see it being the earth straps as the car wouldn't have started in the first place with poor connections there.
My argument for the cam belt was that a snapped belt would cause the engine to stop and might, depending on the engine design, have left valves jammed against cylinders thus preventing the engine turning.
Is the alternator driven by the cam belt or a separate belt? If a separate belt and it's loose a situation can arise where the alternator will spin and produce enough volts to turn-off the charge light but the belt slips when amps are asked for. Thus you drive along thinking all is well but the battery is providing all the power for the electrics, so it goes flat and the engine stops because the electric fuel pump stops. Odd situation but it happened to a car I was in many years ago.

[SparklyKid]

Avatar Image KARL

Question Author
The cam belt was replaced fairly recently, a broken cam belt would not completely kill the electrics. The battery is effectively new, it started the car fine just minutes earlier. Anyone posting comments/advice please base these on the description.

22:07 Wed 09th Oct 2019

A bit rude, if you know so much why ask strangers ?

[Hopkirk]

Are you in a breakdown service?

[KARL]

Murphy of course invoked his famous law at a time of considerable inconvenience when a collection of commitments could be disrupted in one fell swoop - although happily this could have been a lot worse. Nevertheless, I have had a little time to do a bit of experimenting of sorts. My post was aimed at trying to elicit helpful suggestions in a hurry. For those who might wonder how this story develops I can now add a small update.

The mystery remains: With a freshly charged battery installed it starts instantly (very frisky turn of the starter and the engine "takes") and then just as quickly dies. "This is promising" you are inclined to think so you turn the key again to restart, hopefully properly this time. No, the starter won't even turn although it attempts to. I have done this with two separate batteries, both of which I know to be good, and before that I had a jump lead opportunity (stone dead after the initial tiny wrooom, thereafter no improvement with the leads still on and the other vehicle running whereas it should recover within minutes). You can imagine my puzzlement and also how nothing discussed so far appears to suggest/explain what the ailment can be. Something appears to be acting like a short circuit. To me the alternator and/or the starter are prime suspects, but in any case this is an electrical issue.

I am grateful for responses here all of which I know are well meant, although I choose to ignore those replies which are laden with social media syndrome.

[alavahalf]

My first port of call would be as tonyav has already suggested. Have you actually removed the earth straps and cleaned the contact surfaces as previously suggested ?

Simple things first !

[Tilly2]

Take it to a garage.

[ummmm]

My cam belt snapped and it completely killed the electrics.

[KARL]

Earthing fault: It is easy to run a second earth/negative to the body and the engine, even a jump lead will suffice. When that makes no difference then the problem is not an earthing strap/connection fault.

Cam belt: I am not familiar with all modern cars and/or their computerised frills so I can't comment on their behaviour. When a cam belt breaks it is quite possible that some new cars will suffer sensory overload and shut everything down. However, a broken cam belt will at most destroy the engine block and head, the rest will basically be totally unaffected and it can all be reused, including all things electrical. My car under discussion is so basic that the only two things that represent a nod toward modernity are electronic ignition and central locking. In fact, once started and everything being in order it should be possible to remove the battery and it would still run.

The current problem is neither an earth issue or one to do with the cam belt. Today I tried another power-up and rather than try to start I turned the key in the lock - central locking worked and locked the car. I turned the key to unlock: nothing. It turns out you get one chance at doing anything using any of the electrics, take your pick - thereafter it will act as if it has no battery power. I am beginning to think about engaging the services of an exorcist :)

Due to the location and other circumstances, taking the car to a garage (it won't run) and/or using a breakdown service are rather impractical options, hence the scratching around trying to find the fault.

Thank you again for the responses - care to have another stab ?

[bhg481]

Grasping at straws now:

Are you sure the battery is connected the right way round (polarity wise)?

Does anything get hot when you turn-on the ignition (starter, alternator etc) - it could show that power is leaking away through that device.

Is there an alarm system which needs some sort of reset? Sometimes disconnecting a battery can require some sort of reset procedure when you re-connect.

Try disconnecting the electrics from the alternator; I seem to remember from ages ago that a fault in the alternator regulator system could cause the battery to discharge through it. Your car, being a fairly old model, will have a more primitive alternator than more modern ones.

If it's possible, try disconnecting the power cables from the starter motor and bump starting the car.

Keep us informed.

[KARL]

Hi bhg 481. Yep, I feel the same way. I am beset by other pressures so the car remains where it stopped and was pushed off the road. After every new attempt I disconnect whichever good battery I have to hand exactly because I don't want anything to burst into flames as I walk home..... (erm, perhaps a necessary check/verification but, yes, I know + and - apart ;-)

I'll update here whenever a development or anything worth mentioning comes to light. The alarm concern is something I too had in mind (and forgot to mention when thinking about modernity above), there is a factory fitted alarm in the car but it is (deliberately) off. It is beginning to look like I may ultimately have to have the car transported to a good auto electrician, at least if nothing works out and nobody within reach has a solution.

[TonyV]

Karl if you say engine turns over but does not fire,its a fuel or electric problem if you can take spark plugs out and rest them against block you can see if you get a spark.

[vulcan42]

KARL, I'

[vulcan42]

Sorry about that, don't know what happened. I've used this website before and found them very helpful, although it was a mechanical, rather than an electrical, problem.
https://www.justanswer.co.uk/car/

[KARL]

Tony, that's the mystery: The starter turns very briskly and the engine does instantly fire up like a brand new car with a warm engine but within a second or so it dies again. On attempt of a restart, suddenly there is apparently not enough battery power to turn the starter properly although it clearly attempts to turn and when at one point I inadvertently was in gear it moved the car fractionally (but not enough to turn the engine over) so the battery certainly is not totally dead. The same sequence happens with a freshly charged battery plus jump leads and a running engine behind them: Initial momentary life and then total death and no recovery even after several minutes of jump lead feed with a running engine. It really does not make sense to me.

[teacake44]

Faulty coil, coil/pack?? just thought.

[woofgang]

I had this problem with a brand new car years ago. Turned out to be a partially rotted battery lead (are they called HT leads?) no evidence from the outside but rusted within. When the lead connected it would work but when the lead moved slightly and the connection broke the car died. I never got an explanation as to how a brand new car had a rotted lead...it was replaced under warranty though.