PCM 1 and BOSE wiring diagram / replacing stereo

When I bought my car it came with a Pioneer HD-3 installed, which is OK, but I want to replace it with a Kenwood unit as the iPod integration is better on the Kenwood than the Pioneer. I finished ripping out all the old stuff this afternoon, I even plugged in the PCM 1 unit to check it still worked, which it did (well it lit up, I don't have the codes for it unfortunately ). The pioneer unit was connected using both the ISO connectors and also an adapter cable, connecting the RCA pre outs and the remote power switch cable of the Pioneer unit to the yellow, green, blue connector in the car, which I have read connects to the BOSE amp, the 6 CD changer and telephone as follows: Yellow Socket: 1) Line out rear left 2) Line out rear right 3) AF earth 4)Line out front left 5) Line out front right 6) Subwoofer Line out. Green Socket: 7)-12) Special connection for Becker CD changer Blue Socket: 13) AF telephone input 14) Earth- telephone input 15) ¬17) Spescial connection for Becker CD changer 18 ) CD AF earth (AUX) 19) CD AF left (AUX) 20) CD AF right (AUX). I had assumed that what was happening was that the main four speaker outputs (normal wires on the brown ISO) were not being used and that thet RCA Pre-outs were connecting into the BOSE amp via the adapter and yellow plug. With the amp splitting / amplifying etc. to produce the sound out of all 10 speakers. However on closer inspection, I found that the"adapter" was only actually connecting the remote power switch wire, the pins attached to the RCA cables were not connecting to anything on the YBG plug! Can someone please tell me what the various plugs are for on the back of the PCM 1 unit (there are 5 in total), two ISO connectors (brown and black), the multicouloured plug and then two lock in connectors (blue and black) - the last two were not used at all when connecting up the Pioneer unit. Hopefully if I wire the Kenwood in the same way the Pioneer was wired in then it will work - but I would like to make sure I am using the BOSE amp and all the speakers properly! Should probably mention that the previous owner had the Pioneer unit "professionally" installed, so hopefully they did it properly, I am just a little confused at why they connected the RCA plugs up ... to nothing!

I just nipped out and took another look at the wiring, the yellow connector in the car only has one wire on the "car" side, which is the remote power switch wire, none of the other holes on that connector have any wires at all! It would appear then that the Pioneer unit was wired up using the standard brown ISO plug speaker connections into the AMP?!? The car definitely has the BOSE amp in the next to the spare wheel and has all the extra speakers etc. I am just confused at how it is supposed to be wired up with the normal PCM unit, as it obviously didn't use the yellow plug! Does the BOSE amp have a high level input as opposed to a normal low level input that you find on most aftermarket amps?

I took a quick look online for an adapter, and for the "10 speaker upgrade", the following adapter is recommended: This takes the 4 speaker output from the ISO plug, runs it through some circuitry (changing the level?) and passes out to the pins in the red connector which are in the position to connect to the the yellow plug in the car. The adapter I have is basically the same, but instead of the circuit and the ISO plug it connects straight to the low level pre-outs. This would all be fine, if the yellow connector had more than one wire in the car side! If anyone can post up any info on how this should be wired, (i.e. wired via the yellow plug, ISO connector etc.) then it would be greatly appreciated. Rob