Hello all. I've had to replace an alternator (see my other saga of a thread) and it appears in my hurry to buy a replacement, I've purchased one with a different part number.

The alternator that originally came on my car (the one I removed) is P/N 014-154-42-02, which comes back to a Bosch AL9374X. The alternator I mistakenly replaced it with is P/N 000-906-36-22 which on the same site comes back to a Bosch AL9463X.

Now, I've searched these both on the MB-Parts website and found that both are listed as an acceptable part for a 2014 E350 4MATIC which is what I have. When I did the repair, I identified that there was a difference: On the original, the alternator has the voltage regulator connector integrated into the back casing, and three nuts hold the back plastic casing onto the rest of the alternator, showed here. The alternator that I replaced it with has the voltage regulator connector integrated into the voltage regulator itself, and the back plastic panel is held on by one-way plastic snaps (for lack of a better term) as shown here.

The most notable difference (and the reason that during my repair I put the old voltage regulator on the new alternator) is that the original voltage reg has a single-prong female receptacle for the voltage regulator connector. The new alternator has two prongs in that receptacle - they are the same shape and size, but only one of the prongs is plumbed on the male side of the wiring that's attached to the car.

The simple question I'm trying to get is - are these voltage regulators interchangeable? Can I put the new alternator with its two-prong voltage regulator into my single-prong plug on the car and have everything work right? Or must I go buy another alternator to get a voltage regulator (not able to find the regulator alone)?

Any help is appreciated as this is still causing some issues in my car. Many thanks in advance!

 

I am no help with part X-Ref. matching. @konigstiger is the expert wizard.

From the back of my mind, I do believe the single pin or dual pin regulators are interchangeable - So long you use a Valeo OEM regulator with its soft brushes. The copy-cat after market use a hard carbon guaranteed to waste you soft coper rotor. Stay the hell away from no name compatible parts ✌️


Having said that, perhaps your alternator is not the cause of your problem.
Does your W212 suffer from ECU DRAINING YOUR BATTERY WHILE DRIVING?

Then for now, search forum keyword "YOYO" and concider disconnecting ALT. LIN control. This will improve your ownership experience with long lived battery and solid engine performance.

At any rate, note that 12.6Volt is a perfectly good battery float voltage while driving but nothing below 12.3V.

 

I did buy a used Valeo alternator off a car with about 36k miles on it that was wrecked, so it's not a cheapo copycat part. I just wanted to make sure that the piece I was replacing was not going to have some feature unsupported by my car, or vice versa, require some feature my car doesn't have.

I had the alternator tested under load at the parts store and the diodes tested OK, and using the menu in the car I find the voltage to consistently maintain a minimum of 12.6V while driving, and the problem improved markedly upon the replacement of the alternator even while using the old regulator on a new alternator which leads me to believe I have correctly identified the problem. I will look into the posts you mentioned though, thanks for that information.

It should be noted I do not have access to Xentry or Vediamo or any other Merecedes-specific scan tools or coders, so disabling the LIN bus on the alternator could prove difficult.

 

It sounds like your replacement ALT is all right with good voltage control from 14.9V bulk charge down to 12.6V float charge.
No need to disconnect the control wire lead from it then.
✌️

 

If a single command wire to alternator, that is LIN intervention from ECM and alternator has its own charging algo when ECM not commanding anything or taht single LIN command wire disconnected.
Seeing 12.6V only when driving means the LIN intervention is working, but best you test HVAC full blower speed and see if 14.1V is the voltage setting, because that is part of the algo if LIN intervention is implemented and deemed as high load.

I do not like the LIN intervention and have disconnected it and prefer non YOYO 14.1V from alternator own voltage regulator with amperage control so smooth and precise down to 0.5amps only when battery fully charged, I love it.

 

I searched but didnt see which LIN control wire to disconnect, would you have a pic or something. Appreciate it.

 

There are only 2+1 connections to ALT:
1- LIN control (SKINNY)
2- Power output (FAT)
3- GND Reference (ENGINE)

#1 is connected to the regulator connector
#2 is bolted to output post of 3-phase diode rectifier
Disconnecting the LIN control forces the VALEO smart ALT to self control. The OEM regulator is designed to do all that extremely well.

This advanced testing method is beneficial when the ALT control by ECU is proven disfunctional (W212 MY'14...).

LIN free self-control is a great way to get our ALT to power 100% of the car load reliably. This method prevents a lot of battery chaos.


Quint, have your witnessed your W212 deep draining your battery while driving ??

 

Here u go............

 

No I have not actually. I did check the voltage and it showed 12.6v or something like that after startup although I need to do it again since I dont remember when it went to 14v. My truck goes to 14.5v about 30sec after start. Not saying I have a problem just like to know possible solutions to possible problems in the future.

If I leave my car without running it for 3 or 4 days which is rare it shows some indications of low battery but still starts fine. If I run the vehicle for a while it always acts normal on restart. Anyhow thanks for the info both of ya.

 

Quint:
Limited consumers after less than 5 days parked...
Your pick from either :

1. tired old battery
2. abnormal charging
3. Soft-crashed F-SAM control (SCM)
4. all the above favorites combined

A well charged battery current trends towards zero Amp. That's what Surya and I get: great battery numbers.
When reading your instrument cluster battery stats it's up to you to understand the meaning or submit the numbers to us so we can make sense of the trends.
When you see a 12.6V battery display is when you should have a really minimal (1A to 0.2A) current during float voltage.

​​​​​​​Hope your chassis is not affected.
🤞

 

Rock Auto has alternators, new and remanufactured. Less than $300.

https://www.rockauto.com/en/catalog/mercedes-benz,2015,sl400,3.0l+v6+turbocharged,3310432,elect rical,alternator+/+generator,2412

https://www.rockauto.com/en/catalog/mercedes-benz,2015,sl550,4.6l+v8+turbocharged,3310057,elect rical,alternator+/+generator,2412