W203 won't start

[Carlos40]

Hi I need some help if possible so I go out around the corner in car all ok about 10.30 lock the car with remote no probs later on about 2.30 press button to open boot on car it opens get stuff out close boot then go to unlock and go out in it and all is dead unlock with key alarm goes off check voltage on battery says 12v this is a 2003 c200 komp have had no problems before tried other remote that doesn't work either

 

[brucemillar]

Sounds like the alarm has got out of sync. Are you parked near a transmitter of any sort?

I would disconnect the battery for 30 minutes then try again. If possible roll the car some yards from where it is now.

Sent from my iPhone using MBClub UK

 

[Carlos40]

Hi it's parked on drive as normal have had battery disconnected for over an hour then reconnected and still the same

 

[brucemillar]

Is your remote doing anything at all?

Sent from my iPhone using MBClub UK

 

[Carlos40]

No nothing won't operate anything

 

[grober]

Sounds like your battery is flat [ how old is it?] Any thing below 12.6 volts has to be looked on with suspicion. Your alternator may have ceased charging meaning the last few trips have depleted any remaining charge in the battery or a cell in the battery has failed. The alarm has an internal backup battery meaning it will sound for several hours even when disconnected from the main battery. Time to get your battery/charging system tested by an autoelectrician ?

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts when the alternator is charging.

 

[Dec]

Will the hazard lights or side parking lights work?

Dec

 

[Carlos40]

Yes all lights are working had battery on charge all last nite will try this morning when I open with key alarm sounds and no ignition key won't turn either is this because alarm is activated

 

[Dec]

Unlocking and opening the door with the key blade will trigger the alarm, that is normal. If the alarmed is armed, it can only be disarmed by unlocking with the remote fob.
The alarm can also be disarmed by inserting the key into the ignition, if inserting the key into the ignition doesn’t disarm the alarm then the remote key fob may be faulty.
Do you have a spare remote fob?

Set off the alarm again by opening the car door and put the remote fob into the ignition to see if it stops the alarm from sounding.

Dec

 

[Carlos40]

Have tried that with both keys and still the same could it be fm receiver

 

[Dec]

Point the key an inch from the receiver in the door handle, that should work if the RF (radio Frequency) is not working.
Missed that you said you have a spare key in your first post, was the spare key known to be in working order the last time it was used?

Might be wise to unplug the alarm siren until you get to the bottom of the problem.

Dec

https://www.youtube.com/watch?v=BzmpeK1TFfw


[YOUTUBE]BzmpeK1TFfw[/YOUTUBE]

 

[Carlos40]

Both keys were working fine before have tried being next to door as u said and nothing at all

 

[Dec]

Sounds like your battery is flat [ how old is it?] Any thing below 12.6 volts has to be looked on with suspicion. Your alternator may have ceased charging meaning the last few trips have depleted any remaining charge in the battery or a cell in the battery has failed. The alarm has an internal backup battery meaning it will sound for several hours even when disconnected from the main battery. Time to get your battery/charging system tested by an autoelectrician ?

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts when the alternator is charging.

As Grober above, what stat of charge is the battery in now?
Check all the fuses especially the alarm fuse.
Are both connections on the battery clean and tight?

Dec

 

[Carlos40]

Battery is fully charged connections are good have checked fuses all ok it just seams like something has failed if it was receiver would that stop turning ignition key looks like I'm going have to find someone to look at it

 

[Dec]

The key should turn and start the car, even if the receiver or batteries inside the remote weren’t working.
Is the car alarm light blinking?

Dec

 

[Carlos40]

Yes and siren going off until I remove fuse then goes quitter on its own battery

 

[Dec]

With the doors closed, the alarm light is blinking, when you open the door the alarm goes off, is that correct?

Dec

Any idea if the alarm siren is the original, if it is, it is now 13 years old, I think the alarm siren may be something to do with the problem, unbolt the alarm siren and then unplug it… it might go off as soon as you unplug it.
Insulate the alarm siren plug to stop dirt/wet getting to it.

After you unplug the siren put the alarm fuse back.

Dec

 

[Carlos40]

do you know we're alarm siren is and yes siren doesent go off until I open does but blinkers keep going until it all resets itself

 

[Dec]

I mean the tow-way alarm light, it blinks when alarm is armed and car locked with remote.
It’s the switch with car towing hook.

You can see the location of alarm siren in video below not sure which side it’s on on a right hand drive car.
https://www.youtube.com/watch?v=BzmpeK1TFfw

Dec

 

[Carlos40]

Yes interior light flashing inside