I was wondering which terminal on the volvo 850 battery is the negative terminal? Is it the red wire or the black wire with the insulation around it? For my HU install I just disconnected both wires but I would like to know which is the negative wire. Thanks a lot.

 

The positive is the red wire. And the negative is usually a blue wire with black shrink wrap on the end of it.

 

When in doubt look at the marking on the battery or just follow one wire.