'89 300CE charging problem
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'89 300CE
'89 300CE charging problem
I recently bought a 300CE and the battery isn't charging. I'm getting 12.5V at the battery with engine off, 12.0 V with the engine on so the alternator isn't charging. I replaced the voltage regulator this morning and found the brushes extremely worn, but that didn't solve it. The battery indicator on the instrument cluster doesn't light when I turn on the ignition, in fact, none of the idiot lights come on except SRS. I pulled the cluster and the checked the battery bulb, which is fine. I'm about to change the alternator, but I'm doubtful since the lights in the cluster aren't coming on which leads me to think it's something else. Maybe a fuse or wire to the cluster. I've checked the fuses. Any suggestions for why the indicator lights in the cluster aren't coming on and the alternator isn't charging?
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Joined: Mar 2011
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88 W124 300CE
My most immediate though when you said no lights but SRS was the OVP relay.
Over near the battery you should find a small plastic cover near a much larger relay. I did a picture post on benzworld of where and how of checking it.
http://www.benzworld.org/forums/w124...pictorial.html.
Chances are it might have a single fuse OVP still in there which are known for giving silly symptoms without pointing to itself (the bad boy in class who names everyone but himself).
If it's a single **** it off and replace with a genuine (can't stress that enough genuine) MB replacement of the 2 fuse variety !
Next task is to check the fuse box completely.
Are you using copper type fuses or are there some of the cruddy aluminium one's in there. The "ally" ones have a nasty habit of corroding and without beingimmeditaely obvious, break or lose substantial contact.
Finally if the other two things above haven't resolved your issue, it does sound like the alternator itself maybe on the fritz if it's not generating output current back to the battery.
The regulator was the first spot to check but since you have replaced that I am thinking a worse case scenario.
Have you checked how much is coming from the alternator line to the battery ?
If the alternator is outputting what it should with the new regulator - also check the integrity of the battery??
Over near the battery you should find a small plastic cover near a much larger relay. I did a picture post on benzworld of where and how of checking it.
http://www.benzworld.org/forums/w124...pictorial.html.
Chances are it might have a single fuse OVP still in there which are known for giving silly symptoms without pointing to itself (the bad boy in class who names everyone but himself).
If it's a single **** it off and replace with a genuine (can't stress that enough genuine) MB replacement of the 2 fuse variety !
Next task is to check the fuse box completely.
Are you using copper type fuses or are there some of the cruddy aluminium one's in there. The "ally" ones have a nasty habit of corroding and without beingimmeditaely obvious, break or lose substantial contact.
Finally if the other two things above haven't resolved your issue, it does sound like the alternator itself maybe on the fritz if it's not generating output current back to the battery.
The regulator was the first spot to check but since you have replaced that I am thinking a worse case scenario.
Have you checked how much is coming from the alternator line to the battery ?
If the alternator is outputting what it should with the new regulator - also check the integrity of the battery??
