advice please - dead dash

[David-J]

Hi everyone. Been in hospital for 4 weeks for a major op. Went to start my car for 1st time. Bearing in mind the weather has been extremely cold.
2003 W211 E320 CDI
Unlocked from fob OK
Key in ignition - no display on dash = all black
Turned to 2nd position for the usual wait for glowplugs. Still no display.
Engine cranked a little slowly but fired up OK.
There is power to the radio, but the display is faint.
No indicators, cannot switch the headlights lights off, they came on with ignition.
I metered the battery in the boot at 12.3 v
Any ideas ?- please.

 

[Giantvanman]

Was that 12.3v with engine off or on? Does your model have two batteries and have you checked the alternator output voltage?

EDIT: Hope you are on the road to recovery.

 

[David-J]

Engine off. Don't know about a 2nd battery. The handbook only mentions the one in the boot!
If there was a 2nd one would that be in the boot as well, or engine bay?

 

[Slinkee]

Second battery is in the engine bay, under the pollen filter.

 

[Giantvanman]

It would be in the engine bay; I am not familiar with your model of car.
The alternator should be putting out 14.4v (or at least over 14). The fact that the radio works but is dim and the dash is dark with the engine running would suggest an alternator problem but if things are dim or dark with the key in position two/engine off, that would suggest a battery problem. But you seem to have both which doesn't make a lot od sense with 12.3v from the battery!

EDIT: Thanks, Slinkee.

In that case, as I understand it, the boot battery is a back-up so the car can be started. The other one in the engine bay is the one causing the problem in your case.

 

[Slinkee]

This link may help

http://www.mercedestechstore.com/pdfs/W211_advisor/219 HO Dual Battery (ACB - ICC) 11-29-02.pdf

 

[David-J]

Thanks. If that one is dead, would that explain the dead dash etc?
Just popped the bonnet to look. If the battery is under the filter housing I'll struggle to get to it in my present condition. Perhaps Halfords or a local garage will be able to test it. I didn't want to drive it without indicators.