Please&thankyou

Hello

My husband and I bought a used 2006 R350. It ran fine and died in traffic a 2 months ago. It sat due to weather issues and he finally was able to replace the battery 2 days ago. He jumped it and let it run for 30 mins Wednesday. I checked on it Thursday morning, it wouldnt turn over, but all lights and accessories ran fine, no battery warning lights.
I jumped it around 5 pm, let it run for awhile (90 mins). No warning lights or issues, turned off, came back on after being off for 5-10 mins around 7pm. Came home, at 10:15 pm, started with no issues, but Red battery light back on after 1 min. He came home this morning, low voltage warning appeared, then died.
We are assuming it's the alternator. Since this vehicle was really cheap, older, not our main vehicle, we want to do some of the maintenance and repairs.

Any guidance or suggestions on removing and replacing the alternator to see if this fixed the problem?

efzauner

Basic rule, it can get expensive very quickly if you use parts replacement as a troubleshooting method. It could be the alternator, could be a SAM (electronic module) that is bad and is drawing current, or some system that is not shutting down. Having said that, if it is a high mileage car, the alternator will eventually go so may be no harm in changing it out now.


Changing the alternator is no different from any other car. remove the drive belt, remove the + cable and control connector, make sure it doesn't short out on the chassis or engine ground.. unbolt the alternator. Be careful as the steel screws into an aluminum bracket and may be corroded. Ease it out back and forth (same with plugs!)

You can get new or rebuilt units. from Valeo or Bosch
http://www.rmeuropean.com/Make/Merce...?catalogID=006

if you are going to do lots of repairs yourselves I suggest access to shop manual info such as https://www.alldatadiy.com/ there are others.

Please&thankyou

Thank you Efzauner!
we decided to take it to a guy who do small work like brakes and alternators. We assumed it would be too involved for us to do, but the reasons you stated is one reason why we decided to go the this route. Yes, it has a lot of miles (168,000) , but I work from home and don't drive that frequently and with the price, we decided to take the chance.

gforaker

First things first. You need to check if the alternator is putting out power. Get a volt meter and check the voltage while the car is running. It should roughly be around 13.8 v. This is all simple work.

efzauner

You don't even need a voltmeter. The car has one!
put key in position 1
display mileage
press dash light dimmer 3 times and you get the service menu and it displays volts. You can evem start the car and drive

if you are gooing to take the car to a garage at least find a benz speciaist that has a benz code reader.

gforaker

Nice! I thought there was a way for voltage to display, but couldn't recall it.