'Evening all, hoping someone can shed some light on a problem we're having on a late 2005 E60, 520D. A couple of weeks ago my wife noticed a charging fault warning on the screen. On the way home that night the electrical systems gradually shut down, and it limped in through the gate to where it has been sitting since. Battery wouldn't take a proper charge, but took enough to start, voltage didn't increase at all when running, 11.5 ish and gradually dropping, so no juice from the alternator. I figured it had died and killed the battery along with it, so fitted a new battery and a 2nd hand alternator, also new belts while I was at it. Got the BM cables OBD tool working and used that to register the battery (that's cutting a very long story short, but suffice to say the BM cables guys were very helpful, and the problems I had setting it up were entirely my own fault). Still no improvement, no charge and dropping voltage when running. Codes I've read are 4A17 Alternator, 4A27 Intelligent Battery Sensor and also 4212, 4222, 4232, 4242 for Glow Plug – Activation Interrupted on cyl 1-4. I'm presuming that glow plug interruption is to do with the car not having the juice to drive them, but maybe that's not the case.
I've investigated all sorts of other things: the battery cable recall has been done, the IBS is connected but I've no idea if it's working correctly. I've also tried disconnecting it (the blue connector on the negative terminal), but that makes no difference. I read about the brush replacement on the valeo alternators, and sure enough brushes on both old and replacement alternator looked very worn, replaced on both and tried both with no luck. Decided to try a bench test, and set up something simple with an electric drill to drive the alternator, 9V load on the stator, and then +9V onto the small terminal (there are two terminals on the back of the alternator, but only one of these is actually used in the car - that's the one I connected to). Neither alternator did anything useful under this test. To make sure I wasn't just being dumb I did the same test on an older valeo alternator I had out of a clio (admittedly 10 yr older), this gave a very clear result, voltage jumped to over 10 and drill having to work, so I think my test is valid - assuming that the newer alternator isn't completely different in its operation. On the basis of this it looks like the old and replacement alternators are both dud, unlikely I feel, but possible.
Another test, with the alternator fitted I removed the small electrical connector from the back and started the engine. Tested the connector and there's no voltage. So based on my limited understanding that would mean the car isn't calling for the alternator to charge. Or is that correct and the newer alternator is much cleverer than the old ones (ie some sort of trigger signal that I can't measure with voltmeter), or are there multiple failures, or is the alternator ok but the car isn't telling it to deliver. Or the whole alternator issue is a red herring, it's completely fine but IBS problem is triggering the whole disaster. Don't know where to begin to diagnose that.
Maybe unrelated, but weird, when checking around the alternator location for loose wires/plugs etc I noticed a nut that had nearly rattled right off, directly below the alternator on what appears to be an engine mount (!). Fairly sure that shouldn't be loose, and no idea at all how it could be possible. No noticeable signs of damage or wear as a result of this, but it did make me wonder if something could have gotten pulled or pinched as a result. Not that I can see though. Cranked it up tight.
Is there any way of telling if the car is shutting down the alternator? Could an IBS fault be the root problem? My next thought is to take it to an auto electrician and wash my hands of the whole thing, but I would love to get it sorted out myself, any suggestions very welcome, this problem is using up time I should be spending on my kit car. I'm in NI near Banbridge, anyone wanting codes read or help installing software give me a shout, I've made all the mistakes already!
Cheers
Spud
I've investigated all sorts of other things: the battery cable recall has been done, the IBS is connected but I've no idea if it's working correctly. I've also tried disconnecting it (the blue connector on the negative terminal), but that makes no difference. I read about the brush replacement on the valeo alternators, and sure enough brushes on both old and replacement alternator looked very worn, replaced on both and tried both with no luck. Decided to try a bench test, and set up something simple with an electric drill to drive the alternator, 9V load on the stator, and then +9V onto the small terminal (there are two terminals on the back of the alternator, but only one of these is actually used in the car - that's the one I connected to). Neither alternator did anything useful under this test. To make sure I wasn't just being dumb I did the same test on an older valeo alternator I had out of a clio (admittedly 10 yr older), this gave a very clear result, voltage jumped to over 10 and drill having to work, so I think my test is valid - assuming that the newer alternator isn't completely different in its operation. On the basis of this it looks like the old and replacement alternators are both dud, unlikely I feel, but possible.
Another test, with the alternator fitted I removed the small electrical connector from the back and started the engine. Tested the connector and there's no voltage. So based on my limited understanding that would mean the car isn't calling for the alternator to charge. Or is that correct and the newer alternator is much cleverer than the old ones (ie some sort of trigger signal that I can't measure with voltmeter), or are there multiple failures, or is the alternator ok but the car isn't telling it to deliver. Or the whole alternator issue is a red herring, it's completely fine but IBS problem is triggering the whole disaster. Don't know where to begin to diagnose that.
Maybe unrelated, but weird, when checking around the alternator location for loose wires/plugs etc I noticed a nut that had nearly rattled right off, directly below the alternator on what appears to be an engine mount (!). Fairly sure that shouldn't be loose, and no idea at all how it could be possible. No noticeable signs of damage or wear as a result of this, but it did make me wonder if something could have gotten pulled or pinched as a result. Not that I can see though. Cranked it up tight.
Is there any way of telling if the car is shutting down the alternator? Could an IBS fault be the root problem? My next thought is to take it to an auto electrician and wash my hands of the whole thing, but I would love to get it sorted out myself, any suggestions very welcome, this problem is using up time I should be spending on my kit car. I'm in NI near Banbridge, anyone wanting codes read or help installing software give me a shout, I've made all the mistakes already!
Cheers
Spud
