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1987 190D 2.5 Turbo, 1999 Mercedes Benz C230 Kompressor, 1986 190D 2.2 397,000miles
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130 Posts
Discussion Starter #1
I just got my '87 190d turbo 4 days ago. I put a new battery in everything finr for 3 days, went out this morning tried to start it it turned over once and then lights got dim. battery dead. Im going to go get a voltmeter, what fuses etc should i test, also how much power to them should there be while the car is off. Any ideas? thanks.
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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3,103 Posts
Before I would go off measuring the current draw through every fuse I would first check the basic alternator function. You should have a little over 12 volts on the battery with the engine off and then about 13.5 to 14.5 volts with the engine running.
Mike
 

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1987 190D 2.5 Turbo, 1999 Mercedes Benz C230 Kompressor, 1986 190D 2.2 397,000miles
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130 Posts
Discussion Starter #3
Okay will do, what fuses should i check first?
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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3,103 Posts
Okay will do, what fuses should i check first?
I'm sorry but I really don't know. If it's not the alternator than it could be any circuit that is drawing current, or too much current, with the ignition off. Hopefully some other forum members have known suspect circuits and will advise you. Did you check all the interior lights, including the trunk, to make sure they are off with the doors closed?
Mike
 

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1987 190D 2.5 Turbo, 1999 Mercedes Benz C230 Kompressor, 1986 190D 2.2 397,000miles
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130 Posts
Discussion Starter #5
Could it be the radio? its funny, it works while the car is off and key is out?
 

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1990 190E 2.6,.... 1998 ML320, 2005 ML500SE
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3,103 Posts
Could it be the radio? its funny, it works while the car is off and key is out?
When you turn the key off the radio should also turn off. If it is staying on then yes, that would be a good suspect for your problem.
The radio has three 12v sources.
The main one is switched by the ignition. This turns the radio on an off when you turn the ignition on and off.
The second one is constant 12v even with the ignition switch turned off. This is used for the radio security code, antenna control, and will also allow the radio to be turned on manually with the key off if it has that feature in your radio. Usually when the manual feature is used the radio will only play for about 1/2 hour then automatically shut off.
The third one is used for the lighting and is fed from your instrument lighting dimmer control.
Mike
 

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Registered
1987 190D 2.5 Turbo, 1999 Mercedes Benz C230 Kompressor, 1986 190D 2.2 397,000miles
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130 Posts
Discussion Starter #7
Sounds stupid but where is the dimmer control? also when i cut my lights on the radio lights come on only sometimes.
 

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85 190e/8v & 89 420 SEL
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1,073 Posts
The dimmer control is on the instrument cluster. I think it's the left knob sticking out by the temp gauge (outside temp)

My car isn't here or I'd go outside and verify that it's the left one.
 
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