Sterio cutting out at high volume

Hi all my stereo keeps cutting out every time I put it past half volume is there anyone who can help cheers Sam

Have you got a good perminant live feed to your stereo?
Sometimes if the perminant live feed is weak, when you turn your stereo up loud and the stero draws more current if the power feed isn't strong enough your stereo will cut out.
Easiest way to test this is to run a power supply direct from your battery to test if this is the root cause.  

I'm not to sure I will check that is it the red wore I am looking for ? Cheers 

Wire I mean lol

Your best bet is to test the wires with a multimeter due to if your car is like mine, over the years previous owners have messed about and butchered the stereo wiring.
With your ignition off you should have a perminant 12v + feed.

Yh it's always on the back looks like spaghetti junction