Quote Originally Posted by playwme View Post
What head unit are you using? Is it secondhand? Might have an internal fault. Run a temporary wire from the back of the head unit to the battery and try it. That way you narrow down to either your wiring or the wiring in the head unit. If the stereo harness plugs into the head unit check the pins and plugs there too. The yellow one might be loose.
I'm using a brand new Sony Xplod head unit Yeah, that was the last attempt to fix it myself. I'll go and run it now and see how we go.. Hopefully it will shed some light on the situation..

Thanks for the ideas, I'll let you know how I go