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2005 ML350SE, 2014 E350C4
14 Posts
Discussion Starter #1
Hey all,

Over the last month, a strange electrical problem has taken up residence in my 2005 ML350 SE.

After a couple minutes of driving, the power in the car seems to start wavering. I would say at a frequency of about 1-2 Hz, all the lights in the car, including dash, interior, trip computer and exterior lights oscillate in power output. The music volume, air conditioning, and fans also all wobble at the same frequency at the same time.

More curious to me though is that the engine power is also directly affected by this problem. When the car is in drive, but with light enough brakes applied to just stop the car from rolling, the car lurches forward at the same rate of oscillation, with the revs ever-so-slightly matching. At times the problem can be significant and I must consciously apply heave break pressure to stop the car from rocking back and forth at a red light. The engine sounds also confirm the small change in the tach.

I have not had a battery die on me, but I replaced it at 51,000 miles (2009). I am at 77,000 miles now in Sept. 2012.

~Related problem?
Once or twice, and only recently (about a couple months' time) when I would hit a rough bump in the road while traveling ~30-50 mph, the engine shut off completely, but I was able to quickly restart after popping into neutral and continuing without any problems.

I have yet to check the voltage on the battery while experiencing the problem, but after some research I found that there was a TSB on the BOSCH Voltage regulators advising to replace them. This is where I suspect the problem to be, I think the car is just not getting the clean DC power it needs to function smoothly. I think this might explain even the engine oscillation, because the fuel pump/injectors are all electrically powered if iI am not mistaken.

Before I buy the following part, install it myself and report on my findings, I figured I would give a shout out and see if this seems like the right solution. It seems like a simple enough DIY job.

Here is a pic of my alternator I managed to snag with my camera and some hand/body positioning :D

Here is the part I hope will fix the problem.

2005 MERCEDES-BENZ ML350 Parts - Mercedes Benz Parts

(The BOSCH part)

Thanks for your thoughts!
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