Hello everyone - I'm new to this so just thought I'd post a recent experience and would appreciate any feedback.

I bought a used C230 Kompressor about 4 years ago now and up until this past weekend I've really been in love with this car. About 2 weeks ago the red warning light "battery/alternator visit workshop" started to come on. I checked posts on this forum and it seems the most likely suspect was to replace the voltage regulator. Being the lazy lumox that I am, I didn't get round to fixing this problem until too late! (Plus, everything seemed to be functioning fine)

However, on this past Saturday I was losing power going up a slight incline on the highway and had to pull over. I managed to jumpstart my engine and get it home (around 10 miles at this point) but then loads of weird things started happening: First the ABS light, then the SRS light, then the check engine light. What a joy! Around a day before all this happened the "under voltage" warning came on. I'm hoping that I haven't done any further damage to the car by driving the short distance under these conditions but I would dearly love to hear from some feedback from some of the experts and enthusiasts on this forum. Any thoughts as to anything else that may have been affected?

At the very least, this will be an expensive lesson since the shop who is dealing with car have said they don't replace the regulator on it's own (despite it being a separable part!) and it looks like I'm going to be charged for a new alternator. I'm really kicking myself since I could have taken it to a shop (even the dealership) well before I found myself in this situation and probably found someone who would have replaced the alternator alone. BTW, any ideas on how long it would take to replace the alternator? Just trying to weigh out the costs here now....

 

On a '93 I had the entire car shut down despite a 20 minute ride on the highway. In my case, it was the alternator only and the battery recovered. However, if your battery is also four years old, it could be time for a new one. All the warning lights are just systems shutting down because they are a low priority as the car loses battery power. They should not be permanantly affected.
My 2002 C230 coupe had just a battery problem and not an alternator problem. Some diagnostics need to be done.
My first guess is alternator.
GL
BTW, welcome to the forum.

 

Hi gilgorm - thanks for your feedback (and the greeting!) I also have 2002 model, and like you say, the problem was related to the alternator (in my case, the battery is less than 2 years old so I didn't really think this would be the cause). So yesterday, I had the alternator replaced. If anyone's interested, this job cost $330 (parts) + $260 (labour) and took something in the region of 2-2.5 hours. I'm happy to say everything seems to be working fine again.

Some other members in this forum have oft stated they just replaced the voltage regulator as this has been cited as the principal culprit and doesn't necessitate a complete rebuild of the alternator. However, given the age of my car and the fact that I have put just over 100k miles on the clock, to me it seemed a sensible option. A previous service had also recommended a new drive belt so I decided to bite the bullet and just go for a rebuild of the complete alternator unit. This way I feel happy that this problem (or related) won't resurface again any time soon. Losing power on the highway and feeling stranded while other cars are speeding past is no where near as much fun as it sounds.

I know these forums are frequently searched by people in similar circumstances so my recommendation to anyone whose car is showing the "battery/alternator" warning would be to take action sooner rather than later. Thankfully most people are likely far more intelligent than myself and probably don't hang around once these things start happening. But just in case, for around 2 or 3 weeks this warning would intermittently pop up. During this period everything seemed to function as normal and there was no gradual decline in the performance of the car or any electrical components (windows, radio, lights, etc.). Additionally, an all clear from an autozone scan compounded to my complacency on this matter. Everything seemed to go wrong all a sudden.

So, to conclude, if you have a relatively new model with less than 100k miles, it may be worthwhile exploring a replacement of the voltage regulator alone. For those forum members who have posted on this issue and taken this course of action - perhaps you could provide somewhat comprehensive instructions (photos even maybe?) if this was work that you were able to carry out yourself? I believe Bosch and Valeo regulators are available and should cost at most around $100 (possibly a good amount less) for the part so you could save yourself a fair bit this way. For older cars with more miles, it may be worthwhile considering a rebuild of the alternator.

 

One other thing, like gilgorm mentioned, the warning lights have since all gone off again. Comforting.