Battery light on dash (red)

[soggybongo]

hi guys/gals, got in my car yesterday only to find the battery light is lit up on my dash in red. Car started no problem at all, now I have to reverse off my driveway which was fine then a message came up on dash gearbox error and could not select a forward gear. I turned engine off but the would not restart as stuck in reverse gear even though I put it in park before switching off. tested battery with altimeter only to find the battery was at 9.4 v. grabbed the wife car and gave it a jump start and got it back onto my driveway. I removed the battery gave it a trickle charge over night and is now full 12.79v after resting for a few hour. put said battery back in the car started up no problem and drove about 20 mile with no problems at all apart from the battery light on the dash is still on. tested again with altmeter with engine running this time and it seems as though it is not receiving a charge as it's only at 11.4v. 

drop test done on battery and is fine so I know it isn't that, car booked in garage Friday hopefully not too expensive of a fix. 

has been fine the last 6 month nothing came up on the dash at all then bang battery warning light. 

 

[PD Miller]

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Looks like a faulty alternator,. Did you check the voltage with the engine running? I think it should rise to 14 odd volts but someone more knowlegeable will be along with the exact figure. Silly question but the drive belt is ok and turning the alternator? I think if it wasn't you would've noticed other problems on your 20 mile run.

Hopefully not too expensive.

Good luck

 

[soggybongo]

yes mate checked the battery with engine running and only getting 11.4v, also checked drive belt and is fine.

hope it's either the alternator or battery memory module but can't see it being the bmm as I would still see a charge coming from the alternator at the battery with engine running.

 

[soggybongo]

Turned out to be the alternator and not too bad of a replacment cost just shy of £500 fitted with 12 month warranty.  jag at Bradford quoted me near £2000.

Was told the battery is weak but will need replacing so now looking at either a Bosch s4 or s5. trouble is I have a genuine battery on it at the moment so if I replace this with a new one will I also have to have the battery memory module reset?  Will that throw the battery light up again if?

Or do I need to match voltage of old batt to new batt and figure a way of replacing it without loosing battery memory. not bothered about resetting windows or epb but more so battery light kicking in again due to bmm if that makes sense?

 

[PD Miller]

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BMMs and stuff like that all a bit modern for me but I changed my battery without losing codes etc by jumping a supply from a 12v battery to the leads then disconnecting the original battery and replacing it with the new one. Not sure if this would do the trick for you but you wouldn't interrupt the supply during the change over . Obviously you need to remember that the positive lead is live all of the time.

In the past I have found Varta batteries to be excellent and from personal experience with my wife's Range Rover the Varta performs much better than the Bosch which it replaced I believe that they are made by Bosche but wouldn't swear to it.

 

[soggybongo]

thanks pd for your info, buying battery from a local/euro parts supplier and they don't supply varta so stuck with either bosch s4 or s5 £75 difference between them, exile Duracell or lion.   now I don't want to come across as being predantic mate but how do I change over the batteries without interrupting the power supply if the new batt has more volts/less volts than the old. now I know I can get the bmm reset after changing the battery but if there is a way to save money and being as I'm a tight Yorkshire man there must be a way. Just told the wife the heating aint going on till my car is sorted too.

 

[PD Miller]

I used a 12v motorcycle battery as a slave but a 12v car battery would do, and I connected it as you would for a jump start. On my car the pos lead goes to a junction box and I was able to  connect the slave battery pos to it using a cable with crocodile clips and the neg from the slave went to any good earth point. So now the leads would be live when the original battery was disconnected. Then it's just a case of swapping the batteries without the live lead touching an earth or the other lead.. Not sure what difference it would make if the voltage is slightly different between the two batteries. Hope this makes sense and if it works you can turn your heating on and prove that the Yorkshireman's reputation is undeserved.

Just reading back and I noticed that you had the battery off when it all started, did the BBM need to be re-set then?

Good luck and hope your wife has a warm jumper to wear till it's sorted.

[soggybongo]

thanks for you help pd, borrowed my wife car (Mini Cooper s) battery whilst doing the swap and worked a treat. nothing had to be reset.

 

[soggybongo]

next project is to fix a very annoying rattle at low revs whilst at junction/lights coming from passenger door. managed to get the door pannel off, well sort of removed  as I could only get it disconnected 3/4 of the way as it seems to be held on by something right where the wing mirror is and didn't want to force the card so if anyone can give me a clue of a hidden screw or clip would help, I have managed to wrap some sponge tape around the wiring looms behind the door card that has made it quieter but I think it is behind the speaker pannel where the true rattle is so really need to remove the card completely so I can gain access to the speaker pannel and remove that also. thanks in advance guys.