It looks like I need to jump-start my ride-on mower using my petrol A-Class (W177). I've seen plenty of videos where an A-Class is jump-started by other vehicles, but I haven't come across any where the A-Class is used to jump-start another vehicle.

My main question concerns the terminal connections: Should I open the battery cover and connect the black jumper cable directly to the negative terminal of the battery, or should I use the grounding bolt instead when jump-starting another vehicle? I noticed the negative terminal is covered by a plastic cover.

 

First try using the ground bolt then only if it doesn't work, directly on the battery. I recommend calling roadside or buy a seperate jump starter and not use the vehicle but really up to you OP.

 

If your mower's battery is depleted, charge it. If its battery is a goner, buy a new one. Your grass can wait a day.

 

Agree, I don't recommend messing with the car, its electronics is very voltage sensitive.

 

A couple months ago, a neighbor needed a jump start. I drove my 30 year old Jeep over to do the job. Except for a battery maintainer that I sometimes use, nothing else ever connects to my G's jump start terminals for any reason.

 

Computers on wheels, miss the old simpler days...