babylon75

I have a 2003 W211 that will lose power to the cigarette lighter, dome lights, blower fan ac/heater and to the seats after driving a short distance. After turning the ignition off and then restarting the car, the power to the above items will work, however, the longer I drive the car during the day the faster the power shuts off. Any help would be great.
Thank you,
David

vagt6

I have the exact, same problem in my '04 E320. Dying to troubleshoot it.

Anyone?

F1Fan

You get a message on the dash that says something like "battery protection: convenience functions temporary unavailable"? If so, most likely issue is the voltage regulator is wearing out. It is a simple DIY replacement. If you plan on replacing the part yourself, get a Bosch Voltage Regulator, it is roughly $80 and make sure you disconnect the battery before replacing it! Also, your battery may be getting weak, possibly due to the voltage regulator going bad. If you have replaced the battery within the last 2-4 years and have never replaced the VR, I would go with replacing the VR first. Then run the car and see if your voltage on the battery is good. You can google search replacing Voltage Regulator and there will be lots of instructions online.

So in summary, I would check the condition of the VR first. If the brushes are worn out, replace it with a Bosch VR. Do not use any other brand! Other cheaper VRs will cause problems. Then check the condition of the battery. I do not suspect it is the actual alternator as those rarely go bad.

E55Greasemonkey

STOP with the voltage regulators already! This is a 17+ year old platform, the entire alternator should be replaced. The urban legend of replacing the voltage regulator only stems from a 15+ year old recall when the cars were NEW because MB did not want to pay for a full alternator replacement. Just let it go!

F1Fan

Replacing the VR is not an urban legend. Maybe it is to you, but it sure has SOLVED problems for lots of W211 owners, especially early models that have NEVER had them replaced. So quit your whining and let the OP decide for himself.

E55Greasemonkey

You are propagating POOR and IGNORANT advice, and setting people up for a mechanical breakdown in the near future. Maybe you should go change your oil filter but not the oil?

cetialpha5

Either way will work. The voltage regulator is cheaper than the entire alternator and I think in the early years there were multiple alternators so some people got the wrong ones. After the face lift, it was just easier to change the entire alternator as you couldn't get to the voltage regulator easily. There's also a battery control module that was in the pre-face lift model but not post face lift.

As for the oil, in the old days you used to change the filter every other oil change but now pretty much everyone changes it with every oil change. You could probably still do that if you're using a Fram Ultra cartridge.

vagt6

I'll test the voltage regulator, and the alternator. I've got a 1,000 mile trip from FL to VA ahead of me next week, hoping the A/C fan works REALLY well!

Additional input appreciated, and welcome




vagt6

Well, it's still malfunctioning. Same deal. Both cig lighters work intermittently. Replaced fuses, moved both to front and rear position in the fuse box (there are two positions for the cig lighter fueses: the inward plug makes them hot all the time; the outward, on with ignition switch).

Stumped.

konigstiger

Battery?