Coil pack diagnostics

[03Landrover]

I was wondering what methods there were for testing for a faulty coil pack. I've heard you can reverse the wires to opposite sides and see if miss fire code jumps to the opposite cylinder. Is this safe and will it affect anything electrical? Any suggestions are much appreciated. Thanks

[Bosnian Discovery]

You don't reverse just the wires, you actually reverse the coils along with the wires. So basically take coil pack "A" and wire loom "A" and plug it into the connector of pack "B" and the wires onto the "B" side of the engine. The coil packs are identical and this is perfectly safe to do. Make sure you disconnect the battery and download the plug wire routing diagram so you do not screw up the order of the wires.