I need to jump start my Hyundai with my Volvo XC90. The xc90 battery is under the floor in the boot, and is a PITA to get to.

Under the bonnet, there is a remote +ve terminal, but not a -ve. To use my XC90 as a donor battery, do I actually need the -ve terminal, or can I just use the engine block?

Using the engine block as an earth is spot on 🙂

Read your manual for the xc90 and the hyundai infact.

Check your not about to fry the electics of either cars. Some cars detest jumpstarts or being used to jump.

Others have a proceedure to follow.

xc90 manual is silent on use as a donor. Hyundai is a 10 yr old chugger 4×4 so should be fine.

I was always taught negative lead runs from donor batt -ve to engine block on dead car. Is it ok to go block to block with the -ve lead?

yes block to block should work ok the car is all -ve and that is what you are connecting , though I’d repeat the message that many modern cars electronics are jump start averse

I’ve only ever got jumpstarting to work by going straight from battery to battery on both +ve and -ve

Sounds like a PITA – can you not just bump it?

It’ll be fine on the engine.

Ive just found an internet forum with a Volvo Master Technician saying -ve on the engine block, so should all be fine. Thanks all.