riv187

Hi
I have a 2002 c240. Been having dead battery if car sits 2-3 days. This evening after unhooking charger,, I started car for a while. When I turned it off I waited for lights to go off and was watching for something to be on..dome, glove box,,something. I noticed the LED dash stayed lit. I started and shut off car again,,closed door and waited. Everything else turned off,,but the dash screen.
Whats' wrong????? Why???
Thanks
Brian

Moviela

I need a little help. What is a LED dash?

riv187

The orange 3x5 screen in middle under speedo. the screen that shows the various functions from radio to faults. Sorry if it's called something other than LED.

Carsy

Just wondered how old your battery is ? . These cars electrical systems do very strange things with a battery that is failing.

riv187

The battery is 5 month old. I bought a genuine Mercedes battery from dealer.

Moviela

That is the MFD (Multi Function Display) and is part of the IC (Instrument Cluster.) I am not sure about your car, is the 1998 a W203 or W202 in your neck of the woods?

The first thing to check is the key out current flowing from the battery. It should be less than 100 mA. If the IC is not going to sleep, the lamp for the LCD MFD might not turn off.

If the current draw is higher than that 100 mA, disconnect the IC connector and see if the current goes down. If it remains high, some other item is using the current. You need to drop loads one at a time until you find the bad actor.

You might want to post in the W202 forum, the boys there might have a usual suspect for your dilemma.

samaritrey

He does have a w203 he says it is a 2002 c240.
The IC stays on until the can bus shuts down right? if so the problem could reside else well on the network right?

tommy

One thing he could do is disconnect the MFD and see if the drain goes away, if he can stand to not drive the car for a while. It wouldn't explain why the MFD remains lit, but it would at least give us reason for the drain. I'm guessing SAM, the way I do on every electrical problem.

I understand Moviela's confusion - the OP should add their 02 240 to their listing of cars owned on their avatar.

outnabout

I had the same problem on my '02 C320 about 3 years ago. The LED display would stay on and drain the battery. I checked all fuses, relays, CANBUS connections, battery and ground points on the car. I had to keep the car on a trickle charger to be able to start it the next morning. One day, I was messing with the battery when I noticed that the problem went away. I found that there was a short in my positive battery cable. I replaced both cables and never had the problem again. No guarantee that this is your problem, but is worth checking. As others have said, these cars do strange things when there are voltage problems (I've owned mine for 8 years and have 207,000 miles).