
Originally Posted by
mr brightside
I'm always reluctant to provide technical help for strangers on the basis that every man and his dog can profess to be an expert at certain things, but as I summited the chevin earlier I noticed a couple googling how to jump start a car at the top car park opposite the mistral chilli place, and decided to break my own rules. They had the leads connected to the dead car well enough, but the live car only had an exposed +ve terminal under a sliding flap with no obvious gnd in sight. This was the subject of the googling. I explained that with all the conductors hidden we would need an engine mount to get a gnd from, not a body bolt, as the engine mount would have at least a 10mm2 connection to the battery -ve. The body gnd link, not being visible, could not be relied upon to take 40A as it was of an indeterminate CSA. I selected an engine mount on the engine side of the rubber mount and gave the jump lead clamp a good wiggle to cut through any surface corrosion, the dead car sprang to life with no problems. I find it annoying that Mercedes would make it so difficult, as it might have been the Merc that needed a jump and they would be letting their own customers down then, not just preventing someone else's rescue.