Is a 2014 Holden Colorado ute positively or negatively earthed?

As a modern, conventional design, your Holden is negatively earthed (or, grounded). That is, the negative terminal of the battery is connected to the car’s body and engine to complete the circuit for the electrics to function.

But it wasn’t always this way, and in the USA and particularly Britain, many makes and models were positively earthed. Farm machinery and motorcycles were also often positively earthed. I’ve even heard that Dodge cars from the 1920s and 1930 were positively earthed in Canada, and negatively earthed in the US.

There’s a theory that negative earthing is better for preventing corrosion due to electrolysis, but it seems not all engineers agree on this. Ultimately, negative earth is the conventional setup today. Just make sure you don’t get it wrong as hooking up a battery the wrong way around in a modern car is a fair chance to blow the computers and other electronics to smithereens.