C250TD battery drain via fuse #30 and other elec faults. PLEASE HELP

[Blackbird]

1999 manual estate. Battery slowly loses charge.
As the cold weather started I assumed the battery was at fault and replaced it. The problem continues. A local auto electrician reported a steady drain but told me to take it to Mercedes as it needed their computer to diagnose the fault.
Cicely, Preston, (independent MB) had it six days and could not identify the fault.
With my very limited knowledge of car electrics and even more limited knowledge of using a multimeter I have identified a constant 0.4 amp current via fuse #30 with everything switched off.
Any help would be appreciated.

There is also another fault that has been going on for months and I hadn't thought of as being related to the above but you may be able to advise.
When the indicators are switched on there is a delay of one second or so before they work and when they are cancelled they continue to flash for another second or two. This fault also occurs with the windscreen wiper. At the same time as these symptoms began I noticed that the electric windows and the rear screen heater became hit and miss as to whether they would operate.
I apologise for my lack of knowledge and this may be a stupid question but are these items contolled by a single relay and is it possible for a relay to become 'sluggish'?
Regards, David

 

[David Pemberton]

Hello

I had a similar problem, not sure though what's on fuse 30 on your car. My problem was due to a faulty heater booster (a device that burns diesel directly to boost the temperature in cold weather). Basically as the weather gets cold the control system for the heater booster tries to turn it on. It isn't meant to happen with the ignition off, but mine had a fault so on cold days it would drain the battery. I had assumed that the cold weather was just showing up the problems of a very old battery. The cold weather was the cause, but the heater booster was the culprit not the battery.

This post explains: http://forums.mercedesclub.org.uk/showthread.php?t=34184

I haven't experienced the other problems you list. But if you let me know what's listed as being controlled by fuse 30 I'll have a think.

Best wishes

David

 

[television]

As David above,,,,, tell us what does not work when fuse 30 is removed.
the correct drain on you car when locked is 30ma

 

[Blackbird]

Great to have a response from you guys. Thankyou. According to the list in the fusebox cover fuse#30 controls circuits for,
Automatic Heater Control,
Air Conditioner,
Engine Residual Heat System and
Instrument Cluster.
When I remove the fuse the Instrument cluster is indeed almost totally dead and so I assume the others are correct and I'm very optomistic re' your replies.
The AirCon has not worked consistently since I bought the car 3 years ago (regassed last year - no change). Sometimes the air would be cool but never cold (outside temp?). The heater functioning is hit & miss, hot air is never a problem but sometimes (not always) that is all I can get and even in winter weather it is unbearable. The separate left and right controls and the fan speed make no difference when it has dropped into 'inferno' mode.
Having looked at the list re' fuses I see that the first 3 items also use fuse #20 and the Instrument Cluster also uses fuse #41.
First of all - can you enlighten me as to how / why more than one fuse relates to the same circuit.
Secondly - when I look at other circuits using fuse #41, I find some of the long standing problems with a delay on indicators and windscreen wash/wipe are also on that fuse. Is this more than coincidence?
I was getting to point where I thought I would have to trade in for a Ford but I really do love this car to bits especially for its economy and ease of parking so all help is greatly appreciated.
Regards, david