W209 CLK55 - Lights flickering after starting the car
All the lights and console work fine on battery. But after I start the car all the lights including the instrument lights start flickering. Do you guys have any idea why??
I have checked all the fuses and battery for connectivity issues. Was't able to find any.
My first thought was the ignition system. Is there anything to replace except fro the Coils and spark plug wires (which I am planning on doing)?
Also, what is this part? Looks like part of the ignition system. Its making a ticking noise as well.

Thanks.
I haven't had any sparks or boosted anybody. Also, the battery seems to be charging fine.
I will check into voltage regulator replacement.
Is there anyway to test the voltage regulator and the alternator?
Meter across the battery terminals will work for both tests.
Meter across the battery terminals will work for both tests.
With engine turned off: 12.8V steady
With engine running: fluctuating between 14.2V - 14.5V
I couldn't find anything in the service history about replacing the Alternator, so I'm guessing it is the original, so its got a 100k miles on it
14.1 -14.2 with minor fluctuations between those values is good.
Can you retest with increased rpm
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Hopefully it will be an easy replacement. I am ordering one now!!!!!
Will let you know how it goes
Another small point if the bank account permits possible look into a new unit as at 100K miles you are on borrowed time as far as bearings go, your choice but for sure the reg.
Happy holidays.
Since you will most likely have the serpentine belt off, check it and any idler pulleys for looseness spin them with your finger if they spin for a long time, get out the wallet and splurge. You want the 3k trip to leave a smile on your face. Enough said starting to feel like Dr Phil
Last edited by Critter; Jul 24, 2014 at 06:20 PM.




- Radar detector power lost (unit is hardwired)
- On starting the car within an hour or 2 of driving it would turn over 2-3 times longer than usual before starting
- I would hear a single beep sometimes when driving
- Dome light sometimes would not come on after starting the car until after several seconds of idle
- The engine would sometimes seem to "skip a beat" at stop lights.
I checked the battery voltage with the engine off and it was about 12.7V; about 14.5 with the engine running.
The battery is the original (so it's about 7.5 years of age)
I had the battery checked at Advance Auto and the was deficient on cranking power. With that bit of validation and the age of the battery I replaced it with their "Platinum" battery. I did note that the new battery is rated at 95 cranking amps vs. 100 for the original. I think I can live with that.
It has only been a few days but the startup cranking is normal, no more beeps, no radar detector going off in the middle of being adolescent, and the cabin lighting comes on immediately.
The engine "missed beat" has not been noticed, but that may not be related to the battery anyway.
This is just info to the masses............
Wish owners of other Benzs could read your post as it would assist them also when it is time to replace a tired battery. Even though you have the 12.7 the battery was running low amperage output.
Load test is the best way to test for sure, but at 7.5 it would already have been changed out in my car, I go 5 years max.


