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I bought a 2010 B200 in Montreal. It is a Honda dealer that let it go for 4200$Cad since it would not start.
I managed to start it by jumping the Starter relay (30pin with 87pin). I went for a drive and the alternator had a big burn electronic smell. Before I blew it, my voltage seems always low even if I would install a fully charged battery. Then OBD2 gave me a code for a failed alternator. I went under the car and the big smell is coming from the alternator.
When I look under the car I feel it is not so difficult to change the alternator myself. It is located really at the bottom.
Did anybody ever did it? Do you have any input or any documentation or a video?
I found an alternator on eBay for 327$Cad. But before I buy it I would like to know it is a DIY job.
Since nobody answered, I decided to give it a try and I succeeded. Yes it is a DIY job to change an alternator on a Mercedes B200 or a W245 car.
If this is useful for you, then you owe me one. Please, put your notes on this forum about a job you did on your B-Class. It is difficult to find any help for the B-Class so I need your help and contribution.
Here are my notes. I translated them from french with google translator so it won't be perfect.
Please note that the following notes also apply for anyone that wants to change the AC Compressor.
Steps to change an alternator or an AC Compressor on a B-Class Mercedes Benz
Tools required:
A set of 12 points imperial sockets (3/8" and 7/16" required) or stars (6legs) sockets... I am not sure how they call them.
Long pincers.
A Serpentine Belt Tool.
A rope or a strong elastic strap to hold the AC compressor.
A standard 13mm socket for the 12V+ connector on the alternator
1 - Disconnect the negative from the car battery.
2 - We raise the front on each side high enough and we put stands. I had to raise the front quite a lot (the passenger side is the more important, probably 16 to 18”) so that the Serpentine Tool Bar could be put at vertical without touching the ground when it is installed on the Tensioner Bolt. I do not raise the back but it could be done, Mercedes says to put the jack under the pumpkin ball and raise it then to put two stands on the two specifics spots.
3 - Now go under the car and remove the PVC protective plate that covers the alternator and AC Compressor. It is three 10mm socket short screws. These are the only non-star screws of this project.
On this picture we see the Serpentine Belt goes on the AC Compressor at the left of the picture and then at the Alternator more at the right. Some B-Class don't have the AC compressor.
4 - Then the belt is removed from the alternator without removing it completely from the other pulleys. A small "Serpentine Belt Tool" bar with a 15mm socket is required. There is not much space so a ratchet will not fit. You really have to get a "Serpentine Belt Tool". It can be found on amazon, ebay, Canadian Tire or in any auto parts store.
5 - Then the two electrical harnesses of the air conditioning compressor (AC Condenser) have to be disconnected. If you have an AC Compressor. If you don't have one, go to steps 8.
6 - Next, unscrew the 4 screws (socket 3/8 ") on the side of the AC compressor, they are 4 inches long. Then unscrew the small 1-1 / 2" (socket 7/16 ") which is on the "back" of the compressor, all of which are accessible.
Those are 12 points imperial sockets. I use them instead of Torx sockets. This kit is cheaper and will work on your normal bolts and nuts on your other cars and will work also on the Mercedes strange stars torx nuts. To find a kit search on eBay or amazon for "Imperial 12 points sockets".
7 - The compressor can then be moved to the driver side. Be careful, there is a clip that holds one of the wire harnesses on top of the compressor. The clip is removed with a long pincers. To help move the compressor even more, I unscrewed the ground wire screw that was next to the casing. I put a large elastic to hold the compressor aside to release the workspace for the alternator.
8 - Then the two very long screws of 8" (socket 3/8") are unscrewed at the bottom of the alternator. These are our longest. When these two screws are removed, the top one will be unscrewed which will not be as long as it is about 6-1 / 4 "inches long (socket 3/8").
See on this picture that the alternator bracket is not in front of it but on the side:
9 - Now it remains to disconnect the electricity from the alternator. If we pull the alternator down it will go down but this will pull the harnesses. The connections are accessible but we do not see well. So I had to find images on the web. There seems to be a plastic protective cap on the 12V+ wire which makes the task even more difficult. This cap has to be pulled out and then the nut is 13mm. The other connector is a connector whose pin is to be pinched, the side of the connector to be pinched is that which corresponds to the back of the alternator.
The alternator is a VALEO. Connector: Robert's Part Number: 601-10182.
My connector was : A 025 545 47 26, 805-198, PA66 GF25, 2009-07-13 :
Be careful, to disconnect this connector you must first pull the grey pin upward to unlock it. Then press the connector with the grey pin and it will work easily. Attention, pour débrancher ce connecteur il faut tirer d’abord la pin grise vers le haut. Lorsqu’elle est en haut le verrou est ouvert et on peut alors la presser de la façon naturelle pour sortir le connecteur.
I will put 5 images of the alternator connectors since it is not easy to work on them. We have to work on a very tiny space on top of the alternator.
On this picture I wrote "Capuchon". This is the french word for "Plastic Cap". Remove this cap and you will gain access to the screw with your socket.
10 - You are done. Pull down the alternator and have it repaired.
Here the diagram of how to reinstall the Serpentine Belt for B-Class:
This picture now will show the Serpentine track to follow for B-Class with or without AC:
Now here the french version:
Déconnecter le pôle négatif de la batterie.
Tout d’abord on lève le devant de chaque côté assez haut et on met des chandelles. Il faut monter beaucoup l’avant, surtout le côté passager car on veut que l’outil pour défaire la courroie puisse tenir à la vertical quand il est fixé au tensioneur sans quoi on aura beaucoup de difficultés. Je ne monte pas l’arrière.
Ensuite on enlève la plaque de protection en PVC. C’est trois vis courtes de 10mm. Ce sont les seules vis non en étoile de ce projet.
Ensuite on retire la courroie de l’alternateur sans l’enlever complètement. On utiliser obligatoirement un barre « Serpentine Belt Tool » de faible largeur avec un socket de 15mm. On installe le socket et la barre et la queue pointe vers l’arrière du véhicule. On remonte la barre vers le dessous du véhicule.
Ensuite on débranche les deux harnais électrique du compresseur de l’air climatisé.
Ensuite on dévisse les 4 vis (socket 3/8") sur le côté du compresseur AC. Elles ont 4 pouces de long. Ensuite on dévisse la petite de 1-1/2" (socket 7/16") qui est sur l’arrière du compresseur. Elles sont toutes accessibles.
On peut alors déplacer le compresseur vers le côté chauffeur. Attention, il y une clip qui tient un des harnais sur le dessus du compresseur. On retire la clip avec une pince pointue.
Pour aider à le déplacer encore plus, j’ai dévissé la vis du fil de ground qui était à côté des boyaux. J’ai mis un gros élastique pour retenir le compresseur de côté afin de libérer l’espace de travail pour l’alternateur.
Ensuite on dévisse les deux très longues vis de 8" (socket 3/8") au bas de l’alternateur. Ce sont nos plus longues. Lorsque ces deux vis sont enlevées, on dévisse celle du haut qui ne sera pas aussi longue elle fait environ 6-1/4" pouces de long (socket 3/8") sans quoi elle n’aurait pas pu sortir.
Maintenant il reste à débrancher l’électricité de l’alternateur. Si on tire l’alternateur vers le bas il va descendre mais cela va tirer les harnais. Les connexions sont accessibles mais on ne voit pas bien. Il me faut donc trouver des images sur le web. Il semble y avoir un capuchon protecteur en plastique sur le fil 12V+ ce qui rend la tâche encore plus difficile. Ce capuchon se visse ou se retire et dévoile une noix de 13mm. L’autre connecteur est un connecteur dont il faut pincer le côté, le côté du connecteur qu’il faut pincer est celui qui correspond à l’arrière de l’alternateur.
L’alternateur est un VALEO.
Voilà, il ne reste plus qu'à tirer l'alternateur vers le bas et le faire réparer.
Now here are my notes about purchasing a rebuilt alternator for my B-Class B200 Mercedes Benz.
First enter your car VIN on this website to decode your car's information. You will get your engine and transmission number. Those two numbers are required to determine which alternator you will need in the following table.
Here is the list of alternators for the various B-Class base on your engine and transmission numbers:
MERCEDES A-CLASS (W169) A 150 (169.031
169.331) 09/2004 -
06/2012 1498 70 95 M 266.920 Hatchback
IMPORTANT NOTES: To: 03/2008; Engine Code: 266.920; For vehicles with automatic climate control; Transm. Type: 716.520,722.800
MERCEDES A-CLASS (W169) A 160 CDI (169.006
169.306) 09/2004 -
06/2012 1991 60 82 OM 640.942 Hatchback
IMPORTANT NOTES: from MY: 04/2008; Engine Code: 640.942; For vehicles with air conditioning; Transm. Type: 716.522,722.800
MERCEDES A-CLASS (W169) A 170 (169.032
169.332) 09/2004 -
06/2012 1699 85 116 M 266.940 Hatchback
IMPORTANT NOTES: To: 03/2008; Engine Code: 266.940; For vehicles with automatic climate control; Transm. Type: 716.520,722.801
MERCEDES A-CLASS (W169) A 180 (169.032
169.332) 04/2009 -
06/2012 1699 85 116 M 266.940 Hatchback
IMPORTANT NOTES: Engine Code: 266.940; For vehicles with air conditioning; Transm. Type: 716.520,722.801
MERCEDES A-CLASS (W169) A 180 CDI (169.007
169.307) 09/2004 -
06/2012 1991 80 109 OM 640.940 Hatchback
IMPORTANT NOTES: from MY: 04/2008; Engine Code: 640.940; For vehicles with air conditioning; Transm. Type: 716.640,722.800
MERCEDES A-CLASS (W169) A 200 (169.033
169.333) 09/2004 -
06/2012 2034 100 136 M 266.960 Hatchback
IMPORTANT NOTES: To: 03/2008; Engine Code: 266.960; Transm. Type: 716.521,722.801
MERCEDES A-CLASS (W169) A 200 CDI (169.008
169.308) 09/2004 -
06/2012 1991 103 140 OM 640.941 Hatchback
IMPORTANT NOTES: from MY: 04/2008; Engine Code: 640.941; For vehicles with air conditioning; Transm. Type: 716.640,722.800
MERCEDES A-CLASS (W169) A 200 TURBO (169.034
169.334) 09/2005 -
06/2012 2034 142 193 M 266.980 Hatchback
IMPORTANT NOTES: Engine Code: 266.980; For vehicles with air conditioning; Transm. Type: 711.641,722.801
MERCEDES B-CLASS (W245) B 150 (245.231) 03/2005 -
11/2011 1498 70 95 M 266.920 Hatchback
IMPORTANT NOTES: from MY: 05/2005; To: 03/2008; Engine Code: 266.920; For vehicles with automatic climate control; Transm. Type: 716.520,722.801; For taxis; For vehicles with towbar
MERCEDES B-CLASS (W245) B 170 (245.232) 03/2005 -
11/2011 1699 85 116 M 266.940 Hatchback
IMPORTANT NOTES: from MY: 05/2005; To: 03/2008; Engine Code: 266.940; For vehicles with automatic climate control; Transm. Type: 716.520,722.801; For taxis; For vehicles with towbar
MERCEDES B-CLASS (W245) B 170 NGT (245.233) 04/2008 -
11/2011 2034 85 116 M 266.960 Hatchback
IMPORTANT NOTES: To: 06/2009; Engine Code: 266.NGT; For vehicles with automatic climate control; Transm. Type: 5M,CVT6; For taxis
MERCEDES B-CLASS (W245) B 180 (245.232) 04/2009 -
11/2011 1699 85 116 M 266.940 Hatchback
IMPORTANT NOTES: To: 09/2011; Engine Code: 266.940; For vehicles with automatic climate control; Transm. Type: 716.520,722.801; For taxis
MERCEDES B-CLASS (W245) B 180 NGT (245.233) 04/2008 -
11/2011 2034 85 116 M 266.960 Hatchback
IMPORTANT NOTES: from MY: 06/2009; To: 09/2011; Engine Code: 266.NGT; For vehicles with automatic climate control; Transm. Type: 716.520,722.801; For taxis
MERCEDES B-CLASS (W245) B 200 (245.233) 03/2005 -
11/2011 2034 100 136 M 266.960 Hatchback
IMPORTANT NOTES: from MY: 05/2005; To: 09/2011; Engine Code: 266.960; For vehicles with automatic climate control; Transm. Type: 716.521,722.801; For taxis; For vehicles with towbar
MERCEDES B-CLASS (W245) B 200 TURBO (245.234) 03/2005 -
11/2011 2034 142 193 M 266.980 Hatchback
IMPORTANT NOTES: from MY: 05/2005; To: 09/2011; Engine Code: 266.980; For vehicles with automatic climate control; Transm. Type: 711.641,722.800; For taxis; For vehicles with towbar
For my B200 2010 I needed this alternator:
Item Name: Alternator
Part Brand: Valeo original equipment
OEM Numbers: 2661540902 / 2661541302 / A2661541302
New Part:
Voltage [V]: 14
Alternator Charge Current [A]: 110
Rotation Direction: Clockwise rotation
Number of Ribs: 5
Terminal/Clamp: without revcounter connector
Here are my three search request for eBay (350CAD$ or 270$US):
Enter this in the search are of eBay:
(301874RI, 443565, 0 986 081 040, CAL15317, 2251541152, 28-5503, 210553, 12090264, 9090431, CA1874IR, 8EL 012 429-341, 8EL 738 211-431, 32437544, LRA02886, 944390904310, 59212679, 2661540902, 2661541302, A2661541302, 210553, 9212679, 2015317, 6332, 437544, 439551, TG11C035, 24-94268) alternator
We can also purchase only the regulator / On peut aussi acheter le régulateur:
Enter this in eBay search field:
(266-154-06-02, 266-154-09-02, A266-154-06-02, A266-154-09-02, 439551, 2542954, TG11C021, TG11C035) (ALTERNATOR, REGULATOR, BRUSHES)
I will never pay 350$ for my alternator so I searched on the "Small ads" and found 3 Alternator/Starter rebuilders shops. They normally charge 123$Cad + Tax = 140$Cad for an alternator. I don't know yet if this is going to be the price. I changed last week my Honda Odyssey 130A alternator and paid 140$Cad total.
One of the rebuilder shops I called today said that I have to remove the alternator first before he can give me a price. Since they rarely repair Mercedes Alternators here in Quebec, he said I will have to give him my Regulator number. He said it is easy to see. Probably we have to remove two screws to see it. Otherwise he said I could drop the alternator to his shop and he will order the regulator and should have it the next day. When they repair it, they change the ball bearings, regulator and many moving parts.
Here are two pictures of the Alternator regulator:
Updates: I will have it rebuid for 175$Cad. I was expecting to pay 123$ since this is what I paid last week for my Honda Odyssey.
The man told me it is more expensive because he will send it to be rewired. He said normally they don't rewire the coils but this is the problem for this Valeo alternator.
New update: The man told me today when he gave me the rebuild alternator that any alternator on this Mercedes has a problem of Verdigris (the copper rust) on the wires and this is why they have it rewired automatically. I then told him that the alternator is installed under the floor directly 8" above the road.
So everybody, be prepared to have this alternator rebuilt every 3-4 years if you live in an aread with salt on the road during winters.
I just reactivated my account here after a few years just to say thank you.
It is indeed a truly great write up, and the sourcing and search details are great info to have.
I have been having a sound coming from the engine and I wasn't sure if it was related to the alternator, tensioner or idler pulley bearings, or even drivetrain related. Looks like it's the alternator...either bearings or the freewheel pulley (always make sure the pulley is good...it freewheels in one direction and should be smooth and quiet).
06-19-2017, 02:06 PM
