..battery lamp behaviour..

[Ecc0]

..I would appreciate, if someone could clarify eventually, what is going on here..to keep it simple, Ill just put steps in chronological order (vehicle is Z4M Coupe):1) Engine started2) Engine idling for about 3 minutes3) Battery lamp on dashboard turn on and stays for about 5 secs and then turn off 4) Engine still idling for about 20 secs5) Battery lamp on dashboard turn on and stays for about 5 secs and then turn off 6) Engine continue idling and battery lamp doesn't switching on anymoreEvery time battery lamp is ON, i can hear engine running kind a 'easier', and when turn off slightly change sound (I guess alternator charging).This recently happen and Im not sure whats going on. Also, I wanna make a note that car is VERY rarely used, and turned on maybe once a week or once in 2 weeks (weekend). So maybe its related to that, I dont know. During drive no problems at all, nothing..car running like a champ, and no battery indicator (or any other) appear. Just during initial startup, its happening what I have described in steps above..any tips ?

 

[seewai]

I just googled "battery light turns on and off" and many many pages were displayed, I picked a couple of posts and they suggest the alternator.

"the alternator could be producing too low of a voltage and this could cause your battery light. try testing the alternator output and see if it is varying too much. usually supposed to be arond 14.5 volts
you could have a bad alternator or a bad voltage regulator.
there is also the possibility of a bad battery but I would get them both tested. good luck and I hope I helped"

"the battery light is never the battery it is the light that tells you the alternator isn't charging the battery
it sounds like a loose belt to me as if it were the alternator the light wouldn't go back off
now if it were a 1996 or newer car the alternator may be controlled by the computer as well
NEVER DISCONECT THE BATTERY ON A RUNNING CAR IF THE ALTERNATOR WAS WORKING IT MITE NOT WORK NOW and it may deploy an airbag"

"Suggest that your alternator is a b it sluggish,or your alternator belt needs tightening."

etc etc....

 

[cannondale>]

your alternator is about to give away

 

[Ecc0]

..any recommendations, where should i order brand new one, genuine ?

 

[cannondale>]

i am not sure. i saw those shop can repair the alternator. new is not cheap.

 

[Ecc0]

..its around 300USD if im not mistaken (brand new one, Bosch), but i have no success in finding any place online to order new one..sigh..but, funny thing is, this issue happen ONLY when i start engine, for a few minutes and then it completely disappear..long as engine is warm, indicator doesnt appear, no matter am I turned engine off or not..only during initial, cold start...could it be a belt or something like that?

 

[cannondale>]

uneven voltage from alternator. maybe still got 30% life

 

[Ecc0]

..which one of these would match my car..there is not much details about exact model alternators are for..

http://www.ebay.com/sch/i.html?LH_I...ake=BMW&_nkw=bmw+2006+alternator&LH_PrefLoc=2

 

[haywire]

Find the part numbers and order the part from parts supplier like Bavarian Auto etc. You can either order original BMW ones or OEM Bosch ones.

For your info I ordered an OEM Bosch, the unit came in a Bosch box but the alternator still have BMW stamped/moulded in the unit. So I guess its the same item repackaged in a Bosch box.

And yeah it sounds like the alternator is on the way out. Not dead yet but getting there.

 

[cw9722]

bro ecco,
i have just change my alternator today,for e63 m6,using Valeo 170amp will do.
Alternator give way will produce many fault code like...power steering half functioning and cause active steering failure fault code,traction controll inactive will cause ABS and DSC code,even aircond can only operate in minimum fan speed....
after change,now everything back to normall.
A tuner who using E60 M5 proven th alternator failure is very normall for M car as the engine rev is very high compare to normall model.
cheers!