how to jump start c220 (1995)

[anyweb]

hi guys, as there isnt much response to http://forums.mercedesclub.org.uk/showthread.php?t=14056 i have to ask how to safely jump start my c220.

I'm afraid that if i connect up the jump leads that i may do damage to the onboard 'computer' and i certaintly don't want to add to my troubles,

my car fails to start and i'm suspecting the battery, so how can i jump start this car safely

please advise

cheers
anyweb

 

[anyweb]

dunno if this is the right way but it's what i just did and it worked so here goes

i connected the earth from the merc to another car's battery earth (that car was running in neutral gear), then i connected the + to the merc and then connected it to the + on the running car

after turning the ignition the merc started, then i disconnected both leads and felt reasonably happy that my car was running

cheers
anyweb

 

[tom7035]

Jump-starting.

Make sure all electrics are switched off. Connect the positive terminals of the batteries. Connect one end of negative to donor battery and the other end to a suitable earth on the car (NOT the battery) - one of the boot/tailgate lock mounting bolts is ideal. Start the engine and run at idle speed, then switch ON all your electrics, lights, r/w demister, heater blower, before disconnecting the batteries in the reverse order of connection. Turn off electrics.

 

[anyweb]

hmm good info,

well i didnt do that but all seems fine, however next time i encounter this issue i'll try it your way

cheers
anyweb

 

[jimsinessex]

Make sure all electrics are switched off. Connect the positive terminals of the batteries. Connect one end of negative to donor battery and the other end to a suitable earth on the car (NOT the battery) - one of the boot/tailgate lock mounting bolts is ideal. Start the engine and run at idle speed, then switch ON all your electrics, lights, r/w demister, heater blower, before disconnecting the batteries in the reverse order of connection. Turn off electrics.

Just to satisfy my curiosity.....

Why is it not recommended to connect to the battery negative (i.e. the earth) of the car being jump started?

 

[Ron Palfrey]

Danger of explosion. Any spark from the final connection will be away from the battery where there can be explosive fumes which could ignite.

Ron

 

[tom7035]

As above.
I also learned from bitter experience when I was much younger and dafter!

 

[jberks]

Point taken, but if that's the only reason I wonder whether it still really applies. In the old days, we had batteries with 6 twiddly lids that we unscrewed to reveal the acid below. We would top these up too. When a battery went flat, the first thing would be to check the levels which would involve opening the battery, releasing any gas. Also these lids had pressure vents so gas tended to be present anyway.

The W202,W203,W210,W211 etc all have sealed for life, internally stored batteries that are mechanically vented outside the car by means of a tube. Therefore in principle, no explosive gas should be present around the battery. You could even argue that there is a higher probability of gas present around the boot lock than the battery as it vents away! (though clearly far too diluted to be explosive). Playing devils advocate to some extent but perhaps the advice is out of date for modern mercs?

 

[Blobcat]

MB have a procedure which is written in the manual.
I always use the +ve & -Ve connections under the bonnet, rather than the battery under the rear seat when jump starting other vehicles from mine. I am also an advocate of switching on the electrics before disconnecting the jump leads.

 

[jberks]

MB have a procedure which is written in the manual.
I always use the +ve & -Ve connections under the bonnet, rather than the battery under the rear seat

That's pretty much the only complaint I have on the 211. No battery posts under the bonnet like I had on the 210. OK the battery is in the boot, not uder the seat, but to get to it, you have to empty the boot, remove the boot floor panel, then remove all the stuff I've hidden in the space saver recess, then undo 2 screw clips, then remove the spare wheel cover!
Hardly convenient when you want to give someone a jump start!

 

[tom7035]

Point taken, but if that's the only reason I wonder whether it still really applies. In the old days, we had batteries with 6 twiddly lids that we unscrewed to reveal the acid below. We would top these up too. When a battery went flat, the first thing would be to check the levels which would involve opening the battery, releasing any gas. Also these lids had pressure vents so gas tended to be present anyway.

The W202,W203,W210,W211 etc all have sealed for life, internally stored batteries that are mechanically vented outside the car by means of a tube. Therefore in principle, no explosive gas should be present around the battery. You could even argue that there is a higher probability of gas present around the boot lock than the battery as it vents away! (though clearly far too diluted to be explosive). Playing devils advocate to some extent but perhaps the advice is out of date for modern mercs?

Yes, you may well be right, I'm just past my sell-by date and old practices die hard.

 

[Stircrazy]

oK but why turn on all electrics? I have not heard this one before.

 

[Blobcat]

oK but why turn on all electrics? I have not heard this one before.

Stops spikes blowing your ECU