Hello, I, absolutely no techvers, wanted to give a different ride Zueg start aid today. In memory I still have engine off, all consumers of both vehicles switch off, red terminal to the plus pole of the unloaded battery, second red terminal to the plus pole of the donor vehicle, black terminal to the minus pole of the full battery, the second black terminal to the mass of the vehicle to be started etc. But, oh woe is minus in the engine compartment of an XC90? The battery is in the back of the trunk, says also the service manual. The plus connection in the engine compartment is above the fuse box in the engine compartment, says the service manual. Of Minus, however, is never mentioned anywhere. Or does it matter – can I stick the clamp to mass instead of the minus connection? Who knows this? If no one knows, I call Volvo, who know that. Or I let the ADAC come, they know that too.