bponce2189

Hi, I own a 2003 s430..my car said "low battery, visit workshop" later that day after i ignored that problem my dashbored stated to display different error messages like ABS,SRS,BAS, and few more i think, then i pulled over because my car started to sputter. I took it to mercedes and they diagnosed it and told me it was the "Voltage Regulator" but they where charging me $816!!!...I bought the part and put it on my self which took me less than an hour!.....I turned my ignition on and my car starts fine, I take it for a run and as i really step on the gas pedal my headlights turn completely off, as I get off the pedal and just drive normal with out me really getting on the pedal they maintain on. NOW on my display it shows me "DEFECTIVE DISPLAY" AND "COOLANT/VISIT WORKSHOP" and my cars voltage is at 11.8 when ON and 12.33 OFF.....I took the battery and alternator to get tested and they are both in good shape??? ANYBODY KNOW ANYTHING ABOUT THIS PROBLEM???

tusabes

try a known good/new battery and see if that solves it.

These particular Mercedes cars are very sensitive to weak batteries and all kinds of errors show up with low batteries.

bponce2189

Alright, Ill try that, but wouldn't a battery charged itself when its on if the alternator is working?

DRTYLNDY

When they are weak they do cause problems. They just get tired and do not perform very well. These cars need a lot of juice to maintain all the crap they have. I would give the battery a try also before anything else.
BUT I will say your symptoms sound kind of weird.

tusabes

if the battery is weak , sometimes an alternator simply cannot charge it anymore and you will tax your alternator too heavily. Alternator is not designed to supplement or charge up a weak old battery. Its to supplement a good, charged battery.

MCam

+1 on the battery. These cars are funky when the battery isn't at 100% charge, mine has been displaying the same error messages (coolant/display) every once in a while, probably related to the extreme cold.

bponce2189

Hi guys!....I took my alternator to a shop a got it tested and was told "it's good", so I bought a NEW battery and put it on.....and still when I go to the menu on the car to see the voltage it reads in between 11.95-12.26??? it just seems that the alternator isn't charging the battery, but supposedly it works fine?????

VERY FRUSTRATED!!

Trinsoca

my cars voltage is at 11.8 when ON and 12.33 OFF.....I took the battery and alternator to get tested and they are both in good shape??? ANYBODY KNOW ANYTHING ABOUT THIS PROBLEM???[/quote]


The voltage has to be higher in order for it to charge the battery. Try using a separate volt meter and with the car running check voltage at the battery terminals. It should be 13v plus. Also check ALL you connection at the battery and alternator. Make sure there are no wires broke inside the wire insulation and connectors at the alternator. You may have to buy a new alternator if nothing else works or carry it to an indy MB and have them check it.

Sher Judge

Check for a leak in your alarm or tracking system, from an accredited Auto Electrical shop. Power leaks, make the W220's go insane, especially if you have ABC fitted, also just get a really good make of battery, rated in your owners manual for your S, or better yet, just buy an original, they will have a proper warranty.