Battery not charging from a new alternator

[Fandango1]

Hey all, a newbie to the forum so firstly hi to everyone.
My 2008 Vito w639 115cdi Auto minibus has a battery charging issue.
Around 6 months back the glow plug warning light came on and I had difficulties starting it on a cold day, sometimes I had to jump it to get it started.
Then around a week ago whilst i was on the road the battery light and seat belt warning lights came on and stayed on, I revved it up to about 2,500 and both the lights went out but the battery light came back on again as the revs came back down.
Now the battery light is on pretty much permanently apart from when you first start it up (comes on after about a minute).

I've changed the alternator, battery (was original merc one on it) and also the aux belt for brand new ones.
Checked with a multimeter the new battery off the car voltage (12.6v) then when attached to car with engine off (same 12.6v) and finally when the engine was running at idle (went up to 12.9v) and then when revving at around 2,500 (went up to 14v) but then back down to idle and after a minute or so the same issue and the voltage dropped down to 11.9 - 12v, also now the EML has come on and there seems to be loss of power at the top end?

Just wondering if any of these symptoms / warning lights might be related to each other at all or if anyone has ever had anything similar or have any suggestions as I'm at a complete loss at the moment.

 

[toolman1954]

Hi,
Welcome to the forum.....When you changed your Alternator did you use the original clutch mechanism from the old Alternator onto the new one? These can seize up and then the belt just slips until you rev it up .
Bottom pulley has a damper on it and they can split, and again the belt then just slips until you rev it up.
Also this van has an ecu controlled charge system. A blue wire runs from the alternator to pin 66 of the Ecu. Using your trusty Multimeter, that wire should be very carefully checked for connection faults at each end -and along its length, sometimes a length of jumper wire can prove the blue wire to be faulty. Its not unusual to get a rubbing on the wire and hence your trouble.
Then, if nothing else, it could be an ECU fault and will need to go onto a Star Diagnostic or perhaps an Icarsoft type derivative to check this out, . Info relevant a 2007 van, but should cover yours.
The diagnostic may help with your bad running also, and clear any saved faults.

Steve.

 

[Fandango1]

Hi,
Welcome to the forum.....When you changed your Alternator did you use the original clutch mechanism from the old Alternator onto the new one? These can seize up and then the belt just slips until you rev it up.
Steve.

.
Hi Steve, thank you. The new Alternator came with a new clutch pulley but I'll try the other things you suggested. Thanks for the response and suggestions

 

[roastbeef]

had similar problem on my trusty old c180 of 1997 vintage ,went to start it one day had a flat battery had no symptoms prior to this.
set about with multimeter found battery to have only 11.9v jump started volts went to 12.9v loaded the system up fell below 12v changed battery and alternator went to 13.3/4 volts loaded up went to 12.5/6v thought I had cured it not greatly though ,one cold morning everything on got a whole load of random lights on some I am sure I have not seen before but no battery light/alternator light car shuddered to a stop I was clueless until the r.a.c man turned up and found the main lead of the back of the alternator was only just about connected by about 3 strands of copper wire enough to pass voltage to extinguish the alternator light but just could not pass amperage now charging 14.3 volts loaded up

 

[Fandango1]

Hi,
Bottom pulley has a damper on it and they can split, and again the belt then just slips until you rev it up.
Also this van has an ecu controlled charge system. A blue wire runs from the alternator to pin 66 of the Ecu. Using your trusty Multimeter, that wire should be very carefully checked for connection faults at each end -and along its length, sometimes a length of jumper wire can prove the blue wire to be faulty. Its not unusual to get a rubbing on the wire and hence your trouble.
Then, if nothing else, it could be an ECU fault and will need to go onto a Star Diagnostic or perhaps an Icarsoft type derivative to check this out, . Info relevant a 2007 van, but should cover yours.
The diagnostic may help with your bad running also, and clear any saved faults.
Steve.

Hi Steve, thanks a quick update:
Bottom pulley damper appears okay but oh my what a job to get to it lol.

Have had it attached to a Star Diag and cleared all fault history but nothing came up with ECU fault.

ECU wire (LIN i think it's called according to Merc Tech) is blue and green but runs to pin 79 I think (definitley not 66 though) on the ecu. I've checked this wire for continuity and voltage and cont'y appears okay but has 8.5v running through it when engine is running (not sure if that's the voltage it should have going through it though). Also the plug on the end of this wire where it attaches to the alternator only has one wire and one female spade connector yet two ports where you'd expect another female spade connector to be housed, the socket on the alternator has two metal male spade connectors on it, is that normal or is there something missing off the end of the wire do you know?

 

[Fandango1]

Hi, I've given up on the answer to this so sold the vehicle as spares or repair.
Anyone know how to close a thread I can't find any info on how to do it lol?

 

[stephenmercedes]

Hi, I've given up on the answer to this so sold the vehicle as spares or repair.
Anyone know how to close a thread I can't find any info on how to do it lol?

No need to 'close' it - it will die it's own natural death, just like your vehicle, and my C240 which too was just sold for scrap due to electrical issues!