eesjunin

Pulling this thread back....https://mbworld.org/forums/c-class-w...need-help.html

nothing has been replaced/added/serviced in a long time...
No electrical parts hve been replaced, all original, battery has been replaced 2-3 years ago ( Adnvanced auto parts)

Yesterday

Was driving from work, highway 45 minutes, and stopped at friends house, left the car running outside, the fogs, radio and headlights on. When got back into the car, 15-20 mins later, the UNDERVOLTAGE CONSUMER DEFECT. Was on along with the CHECK RIGHT FOG LIGHT...i turned off the car and turned back on, nothing flashed.
5 minutes into the drive the UNDERVOLTAGE sign came back... 5 mintes later it was gone....5 minutes after that it came back on...Got to my next destination, turned the car off. Came back out in 15 minutes, started the car...all clear...drove it home 25 minutes, all clear...
Now i would think if the alternator failed...the ALTERNATOR/Battery sign would come up...If the batter was not holding the charge then the ALTERNATOR/BATTERY sign would also be triggered.
Now before i start pulling my Alternator off and going to AUP to check it along with the battery..cant i simly turn the car on, disconnect the battery and see what it does..obviously the car should run regardless if the battery is there or not if the alternator is charging right?
Which symptop points to the regulator? I know once the alternator is out i can check for the wear...but with the original alt from 2001 i would expect it to go at a 9 year mark, right?
Thanks!

eesjunin

Took it for a drive late last night...with Radio, heat, heat seats radio, fogs on...no messages

Drove this morning to work...45 mins highway...no messages

I did call Autozone and priced out a new Alternator, $190
The question is shoudl i just do it...or was that a glitch and my alternator is fine for the next 20-30K?

pcy

Automotive/electrical issues generally don't vanish. They come back, at the wrong time... just when you are late for an appointment and it's raining/snowing :-)

If I were you, I would further diagnose the problem and replace the alternator if that is the part diagnosed as the culprit.

eesjunin

well i did search entire forum...and two things that come up under that message- Battery and Alternator...it doesnt make sense if its the battery, but alternator i can somewhat agree..
I have taken it out before when was dealing with the whole seat module thing and had it tested...so task of removing it and installing it isnt a problem...
what puzzles me the most is that it functioned properly the entire ride to work today... i was expecting a hick up at some point... so if it glitched and i take it out, take it to get tested, what might be the chances its going to claim to be in fully working condition?

Xhale707

Just test the volts of your car running you should be able to tell right then and there if its working correctly or not

TruTaing

It could be the voltage regulator in the alternator. I suppose the regulator might be faulty or failing (this happened to me), and will randomly get these signs (undervoltage blah blah), but testing it might show that it is fine. How many miles do you have on your car? My alternator was pretty recently replaced due to these same issues. the regulator alone could be replaced, but that would involve dismantling the alternator. Might as well swap the whole unit out if you've got a good number of miles on your car.

Test the volts while your car is running AND the messages are up - the results might be different from when there are no messages.

eesjunin

185K miles
thats exactly what i mean...i am having hard time, between yesterday and today, replicating that glitch. With weather getting colder and colder, with no garage, i think the best idea might be just getting it done tomorrow...
Has anyone gotten the alternator from somehwere other for lower price( just asking)? i got quoted $190 by autozone

wsw

I have read in other threads that it is possible to toggle the display to show voltage. Would this be a method that could be used to determine whether the alternator is charging, or does the display only show static (engine off) voltage?

contact148

it can be used when engine running but really buy a mulitmeter VERY usefully for many things besides your car

wsw

Thanks contact148. I have a multimeter, but my thinking was that if the voltage could be displayed when driving, it may be easier to spot when an intermittent problem actually occured and under what conditions.

TemjinX2

check your oem grounds. I think jurkel had a random undervoltage electrical problem and replaced the alternator and still had the same problem. I turned out to be a bad oem ground. He fixed it by adding a additional ground using stereo wire.

eesjunin

Thanks for replies and suggestons:

i was able to duplicate the message...it does that in an idle mode, when driving the message is never on...when in city driving it goes on after 2-3 minutes sitting at the light.
With that said, made it out Advance auto parts to load test the charging system. Battery tested out good, the charging was also good until the 1-2 minutes of idling and went sour when the message went on.
So everything points to the alternator malfunctioning.
@WSW - i saw that too, but could never get it to pop on my screen, might be after-facelift option?
@ TemjinX- you mean battery ground? i know i replaced mine about 2-3 years back so its not OEM anymore...

SO i got the alternator at autozone...and will take car of it this afternoon...will report back on the results...i hope this is it

TemjinX2

there's a battery ground and there engine grounds located through out the engine.

I would check the engine grounds. There usually the wires thats attached to the engine and the other side is connected to the chassis.

Since your in boston, I assume they put salt on the roads during winter. The salt might of oxidized the copper wires and increased the resistance of the wire.

I would just check them and if you see rust, sand it off or replace it with a smilar size wire or larger.

Here's jturkel's thread.

https://mbworld.org/forums/c32-amg-c...or-help-3.html

eesjunin

Thanks...so replaced the alternator...loaded the system up...no errors...drove around the town with the heat full blast, lights/fogs on...radio blasting...no error

I think this concludes the problem...going out to Boston tonight we'll see how it will behave..
I also cleaned contacts and checked the battery ground like new...i'll have to look at that link and check that body ground...

edgarinho10

I agree. While you have been lucky thus far, what if it just goes out completely when you need it the most. It's best to take care of it while you can before you screw yourself over.

edgarinho10

It might be that you need a stronger/new battery. The battery in my car went bad about 2 years ago, went to auto zone for another one. Funny thing is that it was running on a much smaller, weaker, defective battery. That might be it.

samaritrey

eesjunin do you know what brand of alternator you had and which one was the refub? just curious because i have a feeling that at 151k i am not that far behind you for mine to die on me and the auto zone one is a heck of a deal.

eesjunin

Yes, the one that was in the car was the original Bosch ( and Advance auto parts carry that one for $250 with 2 year warranty)... I end up going with Duralast with lifetime warranty for $180... i could not find anywhere where it said refurbished, the only stap said manufactured in Mexico.
Eah 185K is alot for any electrical part thats constantly in use...i am impressed that it didnt disintegrated and just fell apart.

So 3 days of driving with the new Alternator- consensus is that all is good! Its working, no errors and battery/charge system is producing the required voltage.

samaritrey

well i actually figured out mine because i was changing the power steering fluid and was under there i saw that i have a valeo alternator. I don't like them because of there bad radiators but i guess they can make an alternator. I am just glad my car has the behr radiator.

Umustdv8

You got lucky. I just installed a refurbished alternator from Advance Auto and it caused error messages or was bad. I had to upgrade it to a new one. There's no way yours is new for $190. A new one from MB is around $900 and I got a new Bosch from Advance Auto for $472. My refub was $250.

eesjunin

Really? it might be refurb..i just couldnt find anywhere where it would say refurbished..as i said the only stamp i saw was manufactured in Mexico...

pcy

No matter how you look at it (new/refurbished), you can't beat this deal - $180 and LIFETIME WARRANTY for an alternator

Umustdv8

If it works, you're fine. The refub. I had installed still triggered the check "battery/alternator" warning.

TemjinX2

you can buy the oem alternator which is a valeo for $300 online. I think the newer ones might have used a bosch. Its usually the regulator chip that goes bad not the alternator itself. Anyways i'm glad your problem has been resolved.

Umustdv8

The oem Valeo alternator is made by Bosch. Do you have a link where you can get a "new" oem Bosch/Valeo alternator for $300?