2006 X-5 Red Battery Symbol light
 

Today I experienced a red battery symbol light after starting the X-5. THere was plenty of juice to turn over the engine. I drove the vehicle a short distance and shut it down. A few hours later I restarted the engine without incident-no red battery light. All appears normal now.
Could the main computer reset the light? Could this be an early warning sign of a failing alternator? If so, how many labor hours does it reasonably take to change an E-53 alternator? Thanks.

It depends on what engine you have. A red battery light does equate to early
signs of alternator trouble. I've also noticed that on many BMW's I've seen
as they start to fail they make a high pitch sound. Mine went on my X5 like
two months after I noticed the sound.

It may not happen to all failing alternators. Labor and all was right around
$1200 about four years ago on an M62 4.4i. So expect the same with a V8
and slightly less with the M54. The radiator fan has to be removed on the
eight's, I don't think so on the six's.

Thanks for the information. I have a N62 4.4i engine. I will keep monitoring it and making preparations for repair. My indy wants $700 for a new alternator at 3.5 hrs labor ($102.00 per hour = $357.00). So he is coming in at $1,057. I found a new VALEO 170 amp alternator at Pelican for $423.75 so I can get some savings there.

Is 3.5 hours labor reasonable for an E53 alternator change?
Does the radiator need to be removed?
Does it makes sense to replace the two drive belts during the replacement as a preventive measure being they are right there?

It's a good idea to replace the belts while in there. I am not too familiar
with Valeo products (ive heard, but never associated) Here's a post to skim
through about alternators.

http://www.bimmerfest.com/forums/sho...d.php?t=514504

It is a tight fit to work with so radiator removal is necessary.
3.5 hours seems reasonable for an indy. Here's a brief how to on removal.

http://tis.spaghetticoder.org/s/view.pl?1/07/45/83

If you've UNLOCKED your instrument cluster...you can monitor the output of your alternator/charging system when the engine is running if you open TEST 9. When the engine is NOT running and the ignition is in position 1 or 2...then it will reveal the battery's voltage.

A alternator in good working condition should be putting out 12.8volt to around 13.8 volts. If it is spiking consistently above 14 volts (that's too high). Have you checked your belts? A slipping belt or a belt that is cracked and about to split/rip...could also have caused your momentary red battery light...as well as one of the pulleys/belt tensioners.

Here's the instructions on how to UNLOCK the OBC (instrument cluster) so you can access the 21 TESTs that are available:

Thanks for the info; this is helpful.

Thanks for the procedures. I will give it a try.