'05 C55, replaced alternator, still won't charge.
Thread Starter
Newbie
Joined: Jan 2012
Posts: 5
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From: Bernalillo, New Mexico
Silver 2005 C55 AMG
'05 C55, replaced alternator, still won't charge.
I replaced my alternator with a reman last March (shame on me, I know) and it worked fine for a year. I just got the dreaded Battery/Alternator light again, it wasn't charging so I assumed it failed and dished out the money for a new Bosch. Got it replaced, still won't charge. Battery is good, only about 1.5 years old, and will take and hold a charge from a charger. I've looked all over for a fusible link or some other type of in line fuse and had no luck. From reading other similar posts they seem to say there might be one above the transmission bell housing, but I wanted to be sure before going to that level of disassembly. Anyone know if thise fusible link exists, or had a similar issue that was resolved another way? All of the wiring that is visible from underneath the car is still in the loom, not pinched/ exposed, etc.
Thread Starter
Newbie
Joined: Jan 2012
Posts: 5
Likes: 1
From: Bernalillo, New Mexico
Silver 2005 C55 AMG
I have, battery has same 12.5 volts off and while the car is running. Alternator has voltage when running so I didn't get a dud. My issue has to be somewhere between the working alternator and the battery.
MBWorld Fanatic!
Joined: Oct 2019
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From: Colorado
G550
I agree -- gotta be a fuse or bad connection. Need a wiring diagram at this point.
Member
Joined: Aug 2023
Posts: 75
Likes: 27
C55 AMG
Suspect bad voltage regulator. Did you install a new Bosch unit or get a re-manufactured? Re-mans sometimes come with poor quality replacement regulator.
On a side note, I just did this job because of noisy bearings. I swapped over my Bosch regulator to a used alternator from a R500. All good now.
On a side note, I just did this job because of noisy bearings. I swapped over my Bosch regulator to a used alternator from a R500. All good now.
Thread Starter
Newbie
Joined: Jan 2012
Posts: 5
Likes: 1
From: Bernalillo, New Mexico
Silver 2005 C55 AMG
Not sure whether it was the regulator or the alternator itself, but the Bosch was faulty out of the box. Had it bench tested and it failed, so I exchanged it for another and it is now charging away for me! It was a reman as well, which is why I finally had it tested when everything else seemed to be working fine. Good thing there's so much clearance and it's so easy to install!
Member
Joined: Aug 2023
Posts: 75
Likes: 27
C55 AMG
Not sure whether it was the regulator or the alternator itself, but the Bosch was faulty out of the box. Had it bench tested and it failed, so I exchanged it for another and it is now charging away for me! It was a reman as well, which is why I finally had it tested when everything else seemed to be working fine. Good thing there's so much clearance and it's so easy to install!
Re-man regulator on left. Bosch on right. Note difference in heat sink. The brushes on these two are angled so unusable. My original regulator looked a lot better so in it went.
