[makkan00]

Originally Posted by mistryn

Connector on the left connects to the back of the HU
Lets name it Female Quadlock for ease of understanding
Connector on the right connects to the car wiring
Male Quadlock
Correct, make sure that you take all the additional clips out of your OEM female connector including fiber optic clip, Aux in clip, CCC / CIC clips and connects it to female Quadlock of this harness.

Relay (one with 4 spade connectors – Not sure what to do with this
You do not need to do anything with it.
Also have like a small plastic bit looks like a jumper again not sure where this goes?
That seems to be fibre optic plug. Not clear from the photo though. If it is fiber optic one, you do not need it.




unsure how these connect apart from I know you run one lot down to the amp and then back up to the HU
One has 9 wires and the other 8 wires
Which wire is additional and what colour is that ?



I presume these connect to the under seat subs?

Yes, they seems to be for your subs.



I have no idea what these are for and how they connect?

I guess black wires are to connect to sub and clip connects to sub wires in yoru above photo.
Green coloured wires are jumpers as if your subs OEM clips require it. I do not think you will need it if your OEM sub connectors have only two wires.
One thing that is concerning me is that I have a JL xd400/4 amp, how do I connect inputs as I thought this would have had RCA out puts on the
harness?

Yes, you will require RCA bullets.

I do not know how much you paid for this.
Sell it on this forum and buy mine which comes ready for XD400/4.
Before somebody comes along and accusing me of trading and bla bla, I am just joking.