Car running off of battery. Bad alternator?
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1997 E320
Car running off of battery. Bad alternator?
1997 E320 I6
Last night when I was driving home I noticed that my lights were dim, windows would roll up and down very slowly. I checked #24 from the AC control unit which is the battery/alternator voltage and saw that it was slowly dropping. Then all the systems (ABS, ASR, SRS, etc) started shutting down and throwing errors. Then the red battery charge warning came on in the display. I barely got myself home and it was just dying when I pulled in.
I am pretty sure it is not getting power from alternator so I can rule out the battery as a problem.
I know the alternator brushes could be worn down and need replacement, but before I do that I want to test the relay that switches over from battery to alternator after the car is started to make sure that is not the problem. I am not entirely sure what else there is that could be the problem.
How do I test and make sure that relay is working? what is the testing procedure for the alternator and the relay? I also came across voltage regulator searching the forum. Could that be causing a problem?
Thanks in advance for any help.
Last night when I was driving home I noticed that my lights were dim, windows would roll up and down very slowly. I checked #24 from the AC control unit which is the battery/alternator voltage and saw that it was slowly dropping. Then all the systems (ABS, ASR, SRS, etc) started shutting down and throwing errors. Then the red battery charge warning came on in the display. I barely got myself home and it was just dying when I pulled in.
I am pretty sure it is not getting power from alternator so I can rule out the battery as a problem.
I know the alternator brushes could be worn down and need replacement, but before I do that I want to test the relay that switches over from battery to alternator after the car is started to make sure that is not the problem. I am not entirely sure what else there is that could be the problem.
How do I test and make sure that relay is working? what is the testing procedure for the alternator and the relay? I also came across voltage regulator searching the forum. Could that be causing a problem?
Thanks in advance for any help.
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Check your belt
charge the battery fully for 8 hours with a 10 amp charger.Test alternator output.The electronics that excite the alternator to produce voltage ar in the alternator. You can drive if close by to an ohreilys or whatever auto store and they will test the alternator.Either it ts shot or the vr.Then proceed from there.
www.autohausaz.com carries both.Make sure you get the right brand.
www.autohausaz.com carries both.Make sure you get the right brand.
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Joined: May 2006
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1997 E320
Thank you. Checked the belt, it seems ok but will check again.
Mine has a Valeo. I was thinking of getting a 115 amp Bosch rebuilt by Duralast from autozone with life time warranty (if that is what LLT means).
this item:
http://www.autozone.com/autozone/cat...&parentId=57-0
However from reading several other posts I am not sure if I will run into connection issues. Worst case scenario I will return it and get a Valeo.
Where exactly is the VR located?
Mine has a Valeo. I was thinking of getting a 115 amp Bosch rebuilt by Duralast from autozone with life time warranty (if that is what LLT means).
this item:
http://www.autozone.com/autozone/cat...&parentId=57-0
However from reading several other posts I am not sure if I will run into connection issues. Worst case scenario I will return it and get a Valeo.
Where exactly is the VR located?
MBWorld Fanatic!
Joined: Apr 2007
Posts: 6,171
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Don't think
bosch will fit and the valeo does not have a replaceable vr.Save yourself the time and energy trying to install the bosch.You can install a used with 6 month warranty for about $110 or get a rebuilt valeo .
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1997 E320
Update
Thanks for the input Ohlord. I did take a risk and go with the Bosch rebuilt by Duralast and it is basically a drop-in replacement with the Valeo. What gave me confidence here were the pictures on their site (which I never really rely on) and they looked very similar. The pulley also fit perfectly, although I did have to take it to Sears Auto Center and they were nice enough to transfer the pulley from the old alternator to the new one at no charge. It requires an impact wrench and some tool to grab a hold of the pulley. The bosch does look a tiny bit bigger but I did not have any problems installing it. The only trick is to remove the air filter box entirely as it opens up so much room to work. Here are the steps I took:
- Disconnect battery
- Pull out air filter box
- Take out fan shroud to give more room for hands to move around
- Loosen and take off belt (turn clockwise on the tensioner)
- Disconnect two wire terminals from back of alternator
- Undo the two alternator bolts and it should slide right out.
Very easy job.
- Disconnect battery
- Pull out air filter box
- Take out fan shroud to give more room for hands to move around
- Loosen and take off belt (turn clockwise on the tensioner)
- Disconnect two wire terminals from back of alternator
- Undo the two alternator bolts and it should slide right out.
Very easy job.
