Advice - Batteries!!

[Cyclone1]

After leaving the car at the airport for a few days in the week, the car started fine but the Battery Convenience message came up. The car drove fine for 40 miles then the Battery Convenience warning flashed up again but all still worked fine. Then got to within 5 miles from home and the Radio etc switched off followed by the air con blowers slowing down, with about a couple of miles of my journey left a red warning came up saying battery and alternator fault. Got home, turned it off, gave it a few minutes, tried to fire it up but battery was dead.

Bought a new main battery the following morning, fitted it and everything started working, however the battery convenience warning was still there albeit everything was working. Drove about 40 odd miles since, then today when driving the car, the radio turned off again followed by the aircon fans slowing down. A new red warning sign came up this time of just a picture of a battery with visit workshop. Drove home, switched the car off, gave it a couple of minutes and started it up, started ok albeit a touch sluggish. Suspect the main battery is draining and low on charge.

So what do I do next?

Replace the alternator? (Reason being that the new main battery is already nearly dead)

Replace the auxiliary battery that powers the convenience functions? (Reasoning being that this may already have been failing, but by replacing the main battery it has compensated for the aux battery being dead but is now being drained as a result)

Replace the voltage regulator? (Reason being that the main battery is not retaining charge and have read threads in the past where this is often the issue)

Any advice appreciated.

Jules.

 

[Suky Sangha]

Hello mate I had the same issue a few weeks ago and the result was the alternator. Get it checked out to see if it even works. Good luck

Sent from my iPhone using MBClub UK

 

[stwat]

It sounds like it could be worn brushes in the alternator regulator. I'm not sure on your car but they are usually very easy to replace and not that expensive.

 

[Cyclone1]

Cheers Guys appreciate the input.

Jules

 

[Alps]

Hey Jules, could be the regulator on the alternator also - cheaper to try replacing this first.

 

[Amo]

have you checked what voltage alternator is feeding out?

you can check this yourself from the hidden functions (pressing reset button 3 times on ignition key on 1) I can find you tube video showing how to do this if you not already done this.

It should be close to 14Volts when running.

 

[V8 Supercharger]

you can check this yourself from the hidden functions (pressing reset button 3 times on ignition key on 1) I can find you tube video showing how to do this if you not already done this.

It should be close to 14Volts when running.

I would do this, or atleast take it to your nearest Motor Factors and get them to check it. Its usually a free check and takes a couple of minutes.

But im sure its your alternator at fault, not the battery itself. All the symptoms are there for a faulty alternator.

 

[Cyclone1]

Cheers Guys appreciate the feedback, but have dropped it at my local Indie this morning so we'll see. Bit worried to be honest but fed them my knowledge of what it could be.

Had I known about the Alternator voltage check then I'd have done it so a bit frustrating, however thanks for letting me know it can be done.

The car fired up fine this morning but none of the convenience functions were working. Drove the 8 miles to the indie, switched it off then back on again and it started albeit slightly sluggishly. Suggests the aux battery is dead but also that the "new" main battery is weak and not receiving a charge from the alternator.

Will update once I get the dreaded call.

Jules

 

[Amo]

Good luck and hopefully its not too painful for the wallet.

 

[Cyclone1]

It's the Alternator..............typical! Said it's burnt out and stinks, to be honest on checking under the bonnet yesterday after driving there was a "different" smell under there like a metallic burning smell. So let's hope they can get it done by close of play tomorrow as they aren't sure MB have one to send........ECP have none in stock and are only £30 different.

Jules.

 

[Amo]

Try GSF? Or even carparts4less (they are ECP as well but usually have different stock holding)

 

[Cyclone1]

Garage have had the car 3 days, couldn't get an alternator from MB for 5-7 days due to none in stock in the UK. They then suggested they could get an aftermarket at best Friday!!! I told them to give me 30 minutes to find one, which I did via Acid at MSL, in fact he found 3 suppliers. So yesterday Acid kindly had the alternator driven to Nottingham so they could fit it. It arrived at 3pm at which point they said they would struggle to get it done before 6pm.........The garage called me to say they didn't realise it was such a big job, taking the fan off, draining the coolant etc, so it won't be done until lunchtime today. I politely asked them how long they'd been a Mercedes garage and reminded them they should have some idea of how long it takes to change an alternator. Not looking forward to collecting it.......

Jules.

 

[Amo]

Acid to rescue once again! That man never fails to deliver... Time to change your Indie Jules.

 

[Cyclone1]

I normally go to MSL but as it was battery / alternator related and with work commitments I couldn't get to Brum.

Jules

 

[donshl]

Had the same problem, I took out the alternator myself.

Only had to take the fan out and bit of wriggling it came out. Took it to get refurbished and still running fine.

Andy from Eurocharged came to to fit it ( I had no patience for refitting) and was done in 45 mins.