ML320 red battery warning - no charge
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
ML320 red battery warning - no charge
I have a 2006 ML320 (CDI) with red battery warning.
My wife said it first came on yesterday for a few minutes then went off.
I drove the car twice yesterday (with the voltage display on) and it seemed ok except that it only started charging when the revs were about 1100 rpm (not on idle which I am sure it did before).
Today my wife did 3 trips - first one normal, 2nd one the light came on for a minute - then went off - The 3rd trip it was on for the whole trip and towards the end (it was about 50km) the voltage had dropped to only 11.6volts.
So it is definitely not charging.,,, - now not at all...
Am I right in thinking that it is more likely that this is a regulator problem? I am only saying this in that I thought a diode would not be intermittent? (assume it is not a brushed alternator)
I have a low mileage 2nd hand alternator which has a cracked housing (so am reluctant to just swap it in) but I would be happy to swap the regulator./diode plate etc
Does anyone know of a good link to a removal procedure? I have not found one as yet. Not sure where there is enough room to remove it.
I have access to a hoist tomorrow (and have the car on charge now) so hopefully I can drive it to the hoist so I can get to it underneath as well as on top.
My wife said it first came on yesterday for a few minutes then went off.
I drove the car twice yesterday (with the voltage display on) and it seemed ok except that it only started charging when the revs were about 1100 rpm (not on idle which I am sure it did before).
Today my wife did 3 trips - first one normal, 2nd one the light came on for a minute - then went off - The 3rd trip it was on for the whole trip and towards the end (it was about 50km) the voltage had dropped to only 11.6volts.
So it is definitely not charging.,,, - now not at all...
Am I right in thinking that it is more likely that this is a regulator problem? I am only saying this in that I thought a diode would not be intermittent? (assume it is not a brushed alternator)
I have a low mileage 2nd hand alternator which has a cracked housing (so am reluctant to just swap it in) but I would be happy to swap the regulator./diode plate etc
Does anyone know of a good link to a removal procedure? I have not found one as yet. Not sure where there is enough room to remove it.
I have access to a hoist tomorrow (and have the car on charge now) so hopefully I can drive it to the hoist so I can get to it underneath as well as on top.
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
Sorry about late reply - time difference
I might pull the back off the low mileage alternator I have (but cracked case) and see if I can pull off the regulator in position (doubtful)
Otherwise any help to where to get enough room to extract the alternator would be appreciated
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
Just a progress report
I have the alternator out -had to take the fan unit out and there was clearance between motor and radiator then.
Also loosened electric pump on RHS so I could get alternator between hoses.
BUT
The alternator I had from a late 05 ML320 CDI (with a cracked housing but low mileage) is a VALEO while the one in the car (april 06) is a BOSCH. so there goes my thought of using the regulator from the one with cracked housing.
The bearings sound and feel fine
I have taken the back cover off and there is a heap of crud around the brushes so I assume the regulator/brushes is u/s
Any thoughts?
I have the alternator out -had to take the fan unit out and there was clearance between motor and radiator then.
Also loosened electric pump on RHS so I could get alternator between hoses.
BUT
The alternator I had from a late 05 ML320 CDI (with a cracked housing but low mileage) is a VALEO while the one in the car (april 06) is a BOSCH. so there goes my thought of using the regulator from the one with cracked housing.
The bearings sound and feel fine
I have taken the back cover off and there is a heap of crud around the brushes so I assume the regulator/brushes is u/s
Any thoughts?
Thread Starter
Senior Member
Joined: Oct 2015
Posts: 397
Likes: 23
From: Queensalnd Australia
2006 ML320 CDI (2 of) and 2008 GL320
Thanks for the listing info
My VIN is WDC1641222A123165
On the Bosch (the one out of the car which has done about 225,000km) there is wear where the brushes rub. It has the classic one groove coppery and the other burnt (where brush hasn't been seating properly)
Is there a wear limit on these grooves on the armature?
My VIN is WDC1641222A123165
On the Bosch (the one out of the car which has done about 225,000km) there is wear where the brushes rub. It has the classic one groove coppery and the other burnt (where brush hasn't been seating properly)
Is there a wear limit on these grooves on the armature?
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