Battery Light

[henrym3]

The battery w/l has come on but battery is being charged as normal. OBC show normal voltage, have a little LED readout that plugs into cig lighter and that shows normal charging voltage. Anyone had this problem before, looked on utube and main suggestions are toasted instrument cluster or alternator, got to be an easier/cheaper solution. All suggestions welcome

[Greydog]

Morning Henry
Not had this with the X5 but did have similar with my last AMG E class estate, it started with battery drain Merc Dealer couldn't find anything and fitted a new battery. All OK for a week then same issue but this time charging light would flicker, back to the Dealer tested alternator which was giving full output plus battery tested OK.
Further digging took them a week and a specialist electrician they brought in, it was a diod failing in the voltage regulator. The regulator was changed and I never had the problem again in 3 years.

[henrym3]

Thank you for that Greydog, I don't like throwing parts at faults but in this case it would certainly be cheaper to replace the regulator than pay a auto electrician for an hour of his time and as the alternator output is ok and as the light is on, the bulb works. I think I'll try the regulator route and I swear I won't hold you responsible if it don't work

[Greydog]

The good thing for me the Merc was under manufacturer warranty so no cost to me just the frustration of having a niggly fault on an 11 month old very expensive car.

I accept your absolution
Lets hope it works for you

Dave

[Smeeagain]

my vote os for the FSR hedgehog as they call it

Fairly cheap and easy to install as I recall

[X5Sport]

Seen this once before and on mine it was a regulator issue too.  Needed an oscilloscope to see it as a DC meter can't see the gap in the charge output cycle, but the warning LED can as it works faster.

[henrym3]

Thank you everyone for your input, regulator it is then, didn't really want to dive into the engine bay so soon, had planned to sort out a number of issues later in the year, small oil leak, rad change, power steering pipe weeping, 5k away from g/b and engine oil change.

[PIP1]

I have the same issue on my X5 4.6 is I dont think it is possible to change  the regulator on mine as its a water cooled sealed unit. I am suspecting mine is a cluster issue as i have checked all wiring to cluster as per wiring diagrams and everything checks out ok. 

[lezmtaylor]

You can open up the watercooled alternators and get parts for them (Ebay), I was going to rebuild mine ,but the rear bearing had seized and melted the housing, so a recon unit for £200 was fitted by me.

Lez