While driving on highway all my lights came on and power went out. Vehicle completely shut down and would not restart. I assume it was alternator failure and I have replacement but I would like to know what to check and how to check before replacing alternator. If it is alternator then how do I replace it. I have replaced water pump, power steering pump, tensioner pulley and belt before, just so you know my level of experience. Thanks to anyone who can offer help.

I don't think its the alternator, I think its the crankshaft position sensor. when trying to restart does it turn at all or does it not even try to start whatsoever.

It doesn't do anything at all. The battery is completely dead. I removed the battery and had it tested and charged. Battery is good.

After you charged the battery does the engine crank?

I took the battery to autozone to have it charged. I am going to go ahead and pull out the alternator and take it to have it checked at the same time I'm picking up battery. Will let you know. Thanks for reply!

I put in a newly charged battery and it started right up. I am in the process of taking off the old alternator to have it checked. Removed plug in wire, removed battery wires, removed both bolts holding in alternator. There is a bushing that looks like it is split to hold tension on the alternator.... How do I remove the alternator from here?

Why would you want to remove the alternator? Obviously your battery was bad. If it was the alternator you would have no charging light on......

How do I replace the alternator?

I'm sorry, I should have mentioned the battery was tested as good, I had it recharged and tested again as a good battery. If the alternator goes bad won't the car continue to run until is drains battery then the car shuts down?

No. If the alternator is bad the battery light will lit up. While the car is running check for voltage on the battery it must be 14-14,5volts. Car off 12-12,5 volts. if you get these voltages then your alternator is charging properly.
Don't try to fix what is not broken.....

I do appreciate your response Art. My alternator was tested as bad, can you explain how to move the spacers so I can get the alternator off?

If inspite of the advise you still want to go ahead.......check the PDF

For anyone else out there who needs to replace the alternator, the spacers are merely pressed up against the alternator holding it tight. Simply get a 3 foot long pry bar and pry it out using the a metal surface as pry point on both sides, such as engine and alternator, it comes right out.
Mercedes mechanic told me the alternator was definitely bad and the battery was fine. Next time Art you may want to hold off on giving "advise" when you don't really know what your talking about. I was asking a simple question and not asking you to troubleshoot my problem....

Read the thread from the beginning. Did you mention any were that your alternator was checked before post 11? No, you didn't. It is your responsibility to supply correct info. So before barking at someone who tries to help you make sure you have supplied the correct info.