Good idea or bad idea- DIY jumper cables for a Mercedes

[Shadychris]

The battery is not even a year old, so that should rule that out. But the battery did go dead, though I know that it hadn't been started for a few weeks, but I couldn't even get the doors to unlock through the key fob. And the key fob batteries were fine.

Depends how long you mean by 'a few weeks' really...... If your battery is less than a year old and its going flat after leaving the car parked up, then almost certainly you have a current drain somewhere. Bear in mind the alarm will be using a small amount of current. From what I have read these late 90's - early 00's Mercs seem to have problems in this area with old alarms going bad. My SL was draining it's nearly new battery to the point where the motor barely turned over after about 4 days of standing. I discovered that the N26 ATA module in the boot had been disconnected by a previous owner - presumably in an attempt to resolve. Further pulling fuse 5 in the boot (antitheft warning system\telephone) and locking car only with key (not remote) seems to have solved it for me. Id suggest getting an ammeter and pulling your fuses one by one to check for anything over a few milliamps. Or take it to a good auto electrician if you are unsure about working with electronics. There's some very expensive control modules in these cars that are easily damaged!

 

[brokenthusiast]

Thanks for all the help on this, guys. All it needed was a jumpstart. And that current drain Shadychris has mentioned maybe is accompanied by a coolant leak. But that's gonna be another post.

 

[glojo]

Jump leads won’t start a car that won’t start..

Just

Really appreciate the speedy reply, bob6600. No, I don't want to do this just to crank longer. I just observed that, and thought that it might be useful information; nothing more. It's the 2.2 liter cdi version(143hp). The thing hadn't been started for at least two weeks, so we thought that might be the issue. Hence the jumper cable query. I should've included that in the original post. Another piece of information that might be worth something- sometimes, the car just doesn't want to start, and by that I mean it won't even crank right when we need to go somewhere. Then, a day or two later it inexplicably starts up on the first turn of the key. This happened with the new battery, too.

Hi Broken
Our 216 Sprinter has the 2.2 diesel and it is not uncommon for that vehicle to be left standing for 3 months or even longer. Granted we have had an electrician ensure there is absolutely no drain on the battery, but that engine starts first time every time. I feel it would be nice for it to turn over a few times just to build up the oil pressure but it doesn't and so far so good. out but I for one do not think jump leads will resolve the issue, but has it and by that I mean did it just need that jump start?

Best wishes
John