Octavia Mk2 Aftermarket Head Unit - No Power

[heavymetalthunder]

Hi all, I'm having some trouble with getting my aftermarket head unit (Sony AX3005DB) working in my 2010 Octavia. I have a Quadlock to ISO wiring harness adapter, and connected the yellow cable to the fuse box (using a piggyback fuse holder to an ignition switched fuse) but there is no sign of life to the head unit. I have also tried swapping the red and yellow cables around but no luck. Is there something obvious that I'm missing, or any suggestions on what could be an issue? The car originally had a Bolero head unit and it's an SE model so just has the base sound system (no amplifiers as far as I'm aware). I attach some photos if they help. Thanks in advance.

[heavymetalthunder]

Well for anybody wondering, I sorted it and all is working now. I needed to join the yellow switched power and red continuous power cables from the back of the head unit before it goes into the harness adapter. Glad it was something simple in the end!

[heavymetalthunder]

Just a further update (as I don't see a facility to edit my earlier post) I noticed that the head unit was losing my settings every time I switched off the car. In order to resolve this I ran two new cables to the fusebox, one from the yellow cable to a permanent live fuse and another from the red cable to a switched live fuse. That seems to have resolved things, the head unit switches off with the ignition and remembers my settings!

 

Only minor issue now is the lack of dimming when the headlights are on - the wiring harness does not seem to have a cable for the illumination so I need to find somewhere to tap in to the orange/white striped cable out of the back of the HU. Does anybody have any suggestions? Perhaps somewhere on the heater control illumination?

[langers2k]

I expect the light switch might be the most obvious place?

 

You can also get can-bus modules that'll generate a switched live and lighting wire from the original headunit quadlock.