Can unplugging alternator cause car not to turn over..
Thread Starter
Senior Member
Joined: Oct 2010
Posts: 340
Likes: 8
mercedes 71 280sl. Porsche 930 . Ducati mh900 and ps1000
Can unplugging alternator cause car not to turn over..
Hi guys
got the red battery light come one , has a voltmeter handy in the cigarette lighter and was showing 11-12v
starter the car a few times before I got home.
I also had a few noises that were hard to track .
removed the belt and alt and tried to start the car to run without belt and alt and car now does not even turn over ???
what can this be?
thanks guys
got the red battery light come one , has a voltmeter handy in the cigarette lighter and was showing 11-12v
starter the car a few times before I got home.
I also had a few noises that were hard to track .
removed the belt and alt and tried to start the car to run without belt and alt and car now does not even turn over ???
what can this be?
thanks guys
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
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From: Allentown, PA
'08 GL 320 CDI
To start with, what car is this that you're talking about? Your signature doesn't list a GL. But, assuming you are talking about "some" GL...
Second, it's a little tough to understand what you're saying. Can you re-word this (especially the bolded part): "got the red battery light come one , has a voltmeter handy in the cigarette lighter and was showing 11-12v
starter the car a few times before I got home."
Was the 11V to 12V with the engine running or engine off? Either way, it's way too low. Double check with the volt "gauge" you can access through the center display.
What happens if you re-connect the alternator?
All that said (trying to weed through things here)... charge your battery and get it load tested. Even at 12V with the engine NOT running, it's way too low. Lot's of strange things can happen when a battery isn't up to snuff.
Second, it's a little tough to understand what you're saying. Can you re-word this (especially the bolded part): "got the red battery light come one , has a voltmeter handy in the cigarette lighter and was showing 11-12v
starter the car a few times before I got home."
Was the 11V to 12V with the engine running or engine off? Either way, it's way too low. Double check with the volt "gauge" you can access through the center display.
What happens if you re-connect the alternator?
All that said (trying to weed through things here)... charge your battery and get it load tested. Even at 12V with the engine NOT running, it's way too low. Lot's of strange things can happen when a battery isn't up to snuff.
Thread Starter
Senior Member
Joined: Oct 2010
Posts: 340
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mercedes 71 280sl. Porsche 930 . Ducati mh900 and ps1000
Sorry for not being clear
as the car was running was getting 11-12v.
charged the battery it is now at 12.4 with engine off.
the alt is off the car , and car will not turn over . Is this normal with alt off the car?
gl320 2007
as the car was running was getting 11-12v.
charged the battery it is now at 12.4 with engine off.
the alt is off the car , and car will not turn over . Is this normal with alt off the car?
gl320 2007
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
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From: Allentown, PA
'08 GL 320 CDI
OK, with the engine running it should obviously be higher. Upper 13's to low 14's. I don't know if it's normal for this engine to not start with the alt not wired in - what I was saying was, try wiring it back in, even temporarily without actually mounting it, and see if it allows the engine to crank. That should answer the question.
12.4 is still pretty much at the end of it's life.
12.4 is still pretty much at the end of it's life.
Thread Starter
Senior Member
Joined: Oct 2010
Posts: 340
Likes: 8
mercedes 71 280sl. Porsche 930 . Ducati mh900 and ps1000
This is the latest
all started Friday when I came back from a 2 week vacation.
started the car and heard a whining noise from the belt
then 2 min later the red battery light came on , went to diag mode and saw 11v so I figured the alt was bad . Did a few stops on the way home always with the red warning.
got home and removed the alternator . Tried to start the car and key turns but nothing happens . Just put the new alt on with a full new battery and till nothing.scanned with my star and get codes for glow plug module and shifter module
they both won’t go away. Now also get message car not in P close door and drive to dealer no shifting .
I can sometimes put it in neutral but not always . Can this be front sam related or something else
all fuses are good
also when I turn ignition the voltage does not drop
thanks guys
all started Friday when I came back from a 2 week vacation.
started the car and heard a whining noise from the belt
then 2 min later the red battery light came on , went to diag mode and saw 11v so I figured the alt was bad . Did a few stops on the way home always with the red warning.
got home and removed the alternator . Tried to start the car and key turns but nothing happens . Just put the new alt on with a full new battery and till nothing.scanned with my star and get codes for glow plug module and shifter module
they both won’t go away. Now also get message car not in P close door and drive to dealer no shifting .
I can sometimes put it in neutral but not always . Can this be front sam related or something else
all fuses are good
also when I turn ignition the voltage does not drop
thanks guys
MBWorld Fanatic!
Joined: Dec 2004
Posts: 4,268
Likes: 253
removing the alternator should not affect the ability to crank the engine.
as mentioned, i believe your battery needs to be load tested as it is probably dead and has an internal short between the cells which might manifest with so-so voltage at rest (12.x), but will fall flat on face when loaded up with the starter spinning.
as mentioned, i believe your battery needs to be load tested as it is probably dead and has an internal short between the cells which might manifest with so-so voltage at rest (12.x), but will fall flat on face when loaded up with the starter spinning.
MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
You mentioned you just put a new battery in. Double check that it's healthy with good voltage (should be about 12.8V at rest) and even load test it, just to be sure. Also, check that you installed it correctly and connections are tight. Low voltage can cause all kinds of gremlins.
Voltage won't (significantly) drop when you try to start the car if the starter doesn't kick in.
Voltage won't (significantly) drop when you try to start the car if the starter doesn't kick in.
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MBWorld Fanatic!
Joined: May 2015
Posts: 1,932
Likes: 291
From: Allentown, PA
'08 GL 320 CDI
This is the latest
all started Friday when I came back from a 2 week vacation.
started the car and heard a whining noise from the belt
then 2 min later the red battery light came on , went to diag mode and saw 11v so I figured the alt was bad . Did a few stops on the way home always with the red warning.
got home and removed the alternator . Tried to start the car and key turns but nothing happens . Just put the new alt on with a full new battery and till nothing.scanned with my star and get codes for glow plug module and shifter module
they both won’t go away. Now also get message car not in P close door and drive to dealer no shifting .
I can sometimes put it in neutral but not always . Can this be front sam related or something else
all fuses are good
also when I turn ignition the voltage does not drop
thanks guys
all started Friday when I came back from a 2 week vacation.
started the car and heard a whining noise from the belt
then 2 min later the red battery light came on , went to diag mode and saw 11v so I figured the alt was bad . Did a few stops on the way home always with the red warning.
got home and removed the alternator . Tried to start the car and key turns but nothing happens . Just put the new alt on with a full new battery and till nothing.scanned with my star and get codes for glow plug module and shifter module
they both won’t go away. Now also get message car not in P close door and drive to dealer no shifting .
I can sometimes put it in neutral but not always . Can this be front sam related or something else
all fuses are good
also when I turn ignition the voltage does not drop
thanks guys
Originally Posted by ertech;7584513[b
]just installed the new alternator and the car is back to normal
crazy. A bad alt won’t let the car start
thanks
crazy. A bad alt won’t let the car start
thanks
Thread Starter
Senior Member
Joined: Oct 2010
Posts: 340
Likes: 8
mercedes 71 280sl. Porsche 930 . Ducati mh900 and ps1000
Sorry my English is terrible
I put the old alt on before the new one arrived and it did not start
the new one fixes all.
Thanks all of you
I put the old alt on before the new one arrived and it did not start
the new one fixes all.
Thanks all of you
