Charging issue

[X5IRE]

Hi everyone,

I'm new to the forum and from what I've seen there is a wealth of knowledge on here. Im hoping I can get some advice or help with my 2008 x5 e70 msport

So I bought the e70 last week, got home all seemed fine until the next day it wouldn't start, so I bought a new battery and swapped it only for it to be completely dead again the next day. In the mean time I recharged the old battery and it charged full so the batteries do not seem to be the problem.

I took out the alternator and brought it to my local auto electrician, he replaced the bushings as they were worn and then checked it out of the jeep and it was charging perfectly. However upon putting it back in I checked the voltage in the battery again and still low volts like the alternator was not charging.

Just to be sure it wasn't a ground up front I added a new ground wire and ran it from the alternator to the body of the jeep. Yet again no difference.

Finally I disconnected the IBS on the negative terminal and still no change.

So to recap

Reconditioned alternator and fully tested
New battery and fully charged old battery
New ground running from alternator to body
Disconnected IBS

Any ideas as I'm lost at this stage

Thanks a million

[wcs531]

So just to be clear the car started fine with a new battery but didn't start next day?

Sounds like a battery drain issue. I would search the forum for battery drain issues, the most common one I'm aware of off the top of my head is comfort access handles shorting out. Do you have comfort access?

Also which engine do you have? On the 3.0 diesels the rubber harmonic balancer will crack which drives the alternator, so while the alternator is good it just wont spin. I doubt its a charging issue though since I think it would take a few starts/days to actually die from full charge.

[X5IRE]

Thanks for the reply, yes it started first time with the new battery but I tested when running and was no where near 13/14 volts - That was the reason I took out the alternator, replaced bushings and got it tested before putting in, but once in no extra charge coming from alternator (still no where near 13/14 volts) The serpentine belt/pully are spinning perfectly but no difference in the charge.

Its 3.0 diesel. I was hoping it was a simple battery drain issue but surely the alternator would still be showing the extra charge while running?

I've looked at so many threads between here and different forums but cant seem to find an answer bar everything I've tried above

Thanks again

[jbash87]

Did you register the battery when you installed it?

[X5IRE]

Originally Posted by jbash87

Did you register the battery when you installed it?

I didnt but the previous battery was but didnt make a difference? Surely even if the battery wasn't registered Id have still got a higher volt ready to show the alternator was charging? I tried with the original and new batteries and still no difference in volt when the car is on/off

[jbash87]

The car will charge the battery differently depending on how old it is so I'm curious if maybe there is some fault that re-registering might fix. But I'm not sure if the alternator will output different voltage due to this or not. Figured I'd ask anyways.

If the alternator is known to be good then perhaps there is a ground issue. I know you said you added another ground to the alternator but perhaps one of the other grounds is still causing issues? There should be a chassis and engine ground.

Does your volt meter show different voltages depending on where you ground it?

[X5IRE]

Originally Posted by jbash87

The car will charge the battery differently depending on how old it is so I'm curious if maybe there is some fault that re-registering might fix. But I'm not sure if the alternator will output different voltage due to this or not. Figured I'd ask anyways.

If the alternator is known to be good then perhaps there is a ground issue. I know you said you added another ground to the alternator but perhaps one of the other grounds is still causing issues? There should be a chassis and engine ground.

Does your volt meter show different voltages depending on where you ground it?

I ran two grounds this morning to be sure, one from the alternator to body and other from block to body, both have same volts 11.8-12v with engine running

I checked with both original bmw battery which i now fully charged and the brand new battery

I'm baffled, Im getting it plugged in on friday to see if anything shows up. I've went through thread after thread to look for ideas

[jbash87]

Keep us updated with what you find.