I have just spent all day wiring and tracing the cables for my 100w active sub all the way to the back window of my 02 fabia just to find when i connect it directly to the possitive connector on the battery its not doing anything. the back of the HU has 2 phono type connectors (possibly RCA) they are all connected fine. but not so much as a flicker from the power light on the control.

if anyone has any ideas on why im not getting any power i would really appreciate your help.

Cheers!

In thoery all you need is a permanent live to the 12v '+' terminal. A good earth to the '-' terminal and a 12v ignition or amp feed from the headunit (also known as a remote live) to switch the sub on. The RCA cables carry the signal but wont stop it turning on.

If your headunit doesn't have a "remote live" you could always do a "pikey mod" to it. Connect the "remote" to the positive "+" terminal on the amp with a switch (so you can switch it on and off) Bit of a rough solution but it does work (trust me lol)

Power line run to the battery? Fuse in place? Connected securely?

Earth? Where is a it earted? To the chassis? There is an earth point put in my Skoda just under the passenger side rear speaker, below the parcel shelf. I've earthed mine there with no problems.

Remote cable? Is it connected properly to the remote wire on the ISO loom? Are you sure its the remote wire youve connected it to? It should be blue/ white and blue.