I went to an small independent used car sales to test an 2001 S class, when I turned the key to the first position the dashboard lights came on, but when I tried to start the engine the dash lights when out and it clicked. I assume this is just a flat/low battery. It's been in the dealers for about six weeks without being used, just the odd person starting it up for a few minutes, is that enough to drain the battery?

Will I need radio codes etc if the dealer takes the battery out to charge it overnight?

thanks.

 

Starting the car takes a fairly solid whack at the battery. Doing that a few times without giving it time to recharge and sitting a bit could be enough to kill it. No worries about taking it out to charge it, it'll be fine. The owner's manual covers battery removal, if you want confirmation(which is always nice when asking strangers on the internet.)

 

In addition to what Jack stated just don't jump start it. You would be better off taking the battery out as he suggested. Jump starting these cars if done improperly can cause serious electronic problems.

 

Yes very common for the battery to become too weak to start after several weeks of non use

 

There are no radio codes required, but there are several "reset" operations that will need to be done. The first, and most basic reset is to (with the engine running) turn the steering wheel from lock-to-lock a couple of times. You will probably need to run each window all the way down and hold the button for a couple of seconds, then all the way up and hold the button. Same thing with the sunroof and the steering column, and perhaps the seats.

At the top of the Forum, there are some threads that have a light blue background - those are the "stickies" - reference threads that don't go away. Find the one that says, "start here", and start there. Look for "resets".

Jump starting can be done safely, but the penalties for doing it wrong can bevery expensive.

 

I went to see it today, the car had to be jump started, the battery obviously hadn't been charged up. The 'entry position do not drive' sign is on constantly, all the control to adjust the steering wheel work. As the engine was running I tested all the switches, seat adjustment, airmatic, windows, radio, aircon etc all function normally. As the the drivers headrest was being adjusted the car stalled and didn't have enough battery power to restart. The engine had been running for about 10 mins at this point, it had also been running before I got there as the engine was warm. I'm inclined to walk away, what are our thoughts?

 

Yeah, walk away. You don't want to think it's fixed and only inherit the dealer's issues.

 

The battery is probably old and will not hold a charge

 

If the car is nice, and is cheap, it might well be worth taking a chance on. First thing to check would be the alternator output.

You ca try recharging the battery, but don't get your hopes too high on that. Figure on $150-200 for a battery, as well as possible alternator problems, add that to the lowest price you can weasel out of the (now desperate) dealer, and decide if you need a new hobby...

You are negotiating from a position of strength - use that!