Dead Car Suggestions Please?

[Prudie]

I'd not driven my car since Friday afternoon and when I went to go to work this morning:
Neither remote fob (normal and spare) would open the central locking had to open with the key (would that leave the immobiliser active -??)
Key in ignition - totally dead, no lights, absolutely nothing

My first thought is a catastrophic battery fail, I had to get a lift to work and can't look at it until this evening but what could this be? I can't think anything left on (light etc) would flatten the battery to zero in a couple of days?

[douglas9401]

It sounds like a flat battery or a poor connection of one of the leads.

It's been cold, maybe the battery's at the end of life.

[bhg481]

Battery is favourite. As batteries get older they won't hold their charge for long periods hence they're OK if used daily but will fail if left for a few days. How old is the batery Prudie?

[Arrods]

Not suggesting yours is the same, but my Mazda 6 suffered similar problem. Turned out it was a failure in an earth somewhere inside the system (not the battery earth). It was easily diagnosed and fixed at the garage. Suggest googling your make/model of car with symptoms. There are a number of forums with useful info. Good luck. Do let us know how you get on.

[Prudie]

The battery is no more than 15 months old. I'm still wondering if the fact i opened with the key that the immobiliser is still active - would that make it appear dead? I will let you know and thanks for help so far. It's a well serviced Merc SLK so shouldn't really be clapping out like this.

[donny48]

I presume the remote fob has a battery, has it failed ?

[ummmm]

One time I stopped at a motorway service station so the kids could use the loo and get a snack. When I came out the battery was flat. A kind man jump started it for me and we carried on with our journey with no other problems.

[bhg481]

We have a Volvo which has keyless entry ie, we just pull the door handle and it opens, immobilising the alarm, so long as we have the key in our pocket. The manual says in the case of the immobiliser battery being flat you can open the car with the key but the alarm will not be immobilised until you put the key fob in the "lock" on the dashboard. Your manual should tell you how your immobiliser behaves.
The fact that both of your key fobs failed to unlock the door points to the car battery being flat, rather than the fob battery. No signs of life with the ignition turned on reinforces this; I think if the problem is a bad/dirty connection you would get some low-power things working (dash lights etc) but no joy from high power accessories.
The battery being only 15 months old doesn't mean it's incapable of failing. Were it several years old the age could have been a good indicator but the fact that it's relatively young doesn't exclude battery failure. At that age though I'd expect it to be covered by the car warranty - worth contacting your dealer.

[anaxcrosswords]

Same thing happened with my Honda CR-Z and it was less than 24 hours after previously running it. Not even a flicker of light from the dashboard.
It turned out the interior light HAD been left on, but only because it hadn't properly been switched off, ie the switch position was close enough to ON to trigger it with some sort of vibration, for example closing the door. The RAC guy said the interior light could completely kill the battery overnight, to the extent the battery had to be replaced.
Worth double checking just to see if the interior light switch is completely off.

[Prudie]

That is interesting anax as the interior lights have been playing up lately, either not coming on at all or coming on when you shut the door rather than opening it. I wonder if it could be that? Just wouldn't have thought that was enough to drain the battery completely in 48 hours? would a completely flat battery stop the central locking responding?

[bhg481]

Yes, an interior light left on can flatten AND ruin the battery - it happened to us when one of our grandsons left one on. We were on holiday in France at the time and had to leave the battery on charge overnight for the rest of the holiday; fortunately only a few days left.

[diddlydo]

I assume you have breakdown insurance? Just call them and let them sort it out,

[Prudie]

I do have breakdown but it doesn't include homestart. I'm thoroughly fed up because after OH spending ages out in the cold fog tonight, me too, it won't start from jump leads although all the lights and everything come on with jump leads attached. Starter motor just clicks. The battery is only showing 6.4 volts. Can it just die like that over a weekend (if it's the battery at fault).

[tonyav]

If the battery is totally dead jump leads ( from one car to the other won't start it ). It needs a new battery, Prudie.

[tonyav]

And yes it can die over the weekend if there has been a drain on it.
Probably that interior light problem that you mentioned.

[Prudie]

I've been waiting for you - can you pop over :-))
Can the battery just die out of the blue like that Tony? I should add that it was flat when left for 3 weeks over this Christmas but did start with jump leads and hadn't been a problem until now.

[EDDIE51]

Your alternator may be faulty and not charging the battery correctly. That is the next most likely possibility. It has just happened to my son symptoms similar to yours.

[tonyav]

Sounds like after the christmas drain it probably hasn't had chance to fully recharge ( driving fairly short distances, lights, heater, aircon ect ).
It probably hasn't died out of the Blue most likely a mix of cold weather, something draining it ( ie interior light or glove box light ) and old age.
How old is the battery on your car, Prudie.

[ladybirder]

Have you been taking it on good long runs Prudie, since Christmas? This cold weather and short runs will not keep your battery topped up as I was told by my Recovery man.

[Prudie]

I do normally only do short runs but I've done 2 since Xmas of 2hrs each way including last Thursday. I think it's about 15 months old. All a right pain in behind as it's stuck outside the house, automatic etc. I think I'll start with a new battery.