Clock re-setting

[Weelawser]

Hi folks,
My 2007 z clock keeps re - setting back to 1am about a minute after starting. I have read various posts referring to battery replacement, having just taken the battery out and charging over night it's done the same again. Doesn' t seem to be any problem starting been doing the clock re- set for couple of months now....Does this look like a new battery ?

 

[Silverzedtom]

It certainly sounds like a likely culprit - any indication on it as to how old it is?

Probably not a bad place to start if the battery’s getting on a bit or if you don’t know how old it is.

You could do a cold crank test on it and also see if it holds voltage first but our cars are so sensitive to low voltage it might be worth just getting a new one and if it doesn’t fix the clock you’ll at least know you won’t get caught out with a flat battery any time soon.

 

[Weelawser]

I've had the car 5 years and i think that the BMW garage i bought it from must have replaced it at some point previous to that as it has their name on it and it is a genuine BMW battery.

 

[AaronMc]

I've got a similar issue - doesn't happen on startup but will reset if the engine bogs down pulling away or between 1st and 2nd. Was thinking of bringing it to a dealership at the end of the month as I have a warranty on it and a long drive and a Ctek battery charge hasn't shifted the issue. I'll let you know what/if anything they find

 

[ph001]

If the battery is high resistance, it doesn't matter how well charged it is - the problem is that when you take a lot of current from it (like when starting), the volts drop way down and lots of electrical things reset. You do tend to get pretty lazy turning over of the starter too.

The other possibility is a high resistance connection on the high current wiring / connections from the battery to the engine but a new battery is where you need to start for sure.

 

[AaronMc]

[ref]Weelawser[/ref], did you get to the bottom of this?

For me it ended up being an aftermarket iPod connector installed by a previous owner that caused the clock reset. Unfortunately this was only properly identified after an inspection, battery change and the fitting of a new instrument cluster totalling approx £500 - would've been more expensive if I didn't have the warranty!!

 

[Weelawser]

Cheers AaronMc, my Ipod for Intravee had not been connected for quite quite some time.
I charged and put it back in the car, initially I thought it hadn't cured the problem however the clock now keeps time...Who'd have thought anything as simple as that would be at fault !