Can someone tell me where the negative terminal of the battery under the hood of the Volvo XC90 year 2007 AWD V8 is?
The battery in this vehicle is hidden and is not located under the hood. It is under a deck cover inside the rear of the vehicle.
The above YouTube video shows a couple methods to jump-start this vehicle, one using the positive terminal located under the hood, one using the rear battery location.
It is common and advised to use a frame member as the negative contact for a jump-start, after securing the positive connection to the battery, or in this case to the under-hood connection. The use of a frame member is applicable to both the charging vehicle and the vehicle being charged. When performing a jump-start, sparks can be expected and using a frame location for the last connection, away from the battery, minimizes the risk from exploding hydrogen released by the battery.
When using the under-hood connection, located at the end of the car opposite of the battery, the risk is obviously minimized, but the frame member remains as the negative connection.
If your objective is to disconnect the battery and is not to jump-start the car, open your tailgate and lift the panel covering the recessed storage area. The battery is located in the aft section of that area. Always remove the negative connection first, then the positive. Reverse the sequence (positive first) when re-connecting. If you've ever accidentally grounded the wrench on the positive terminal while working on a battery, you already know this tidbit of information.