MK2 GTI ISO wiring help

[rowlers]

if you've got perm live to both, then it won't switch off with ignition???

[Bushboy]

No it wont.  But it turns off when I remove the facia, which i never leave in the car, so no probs with it not turning off. 

[mattp1983]

The yellow and white wire was the ignition live on mine, have an alpine unit in and had to switch over the live and ignition live to make it work, otherwise it was powering up all the time.

[Bushboy]

hmmm might give that a go then.  Although i like it without the ignition switch as its useful not having to have the ignition on whenever you just want to listen to the radio etc.

[mattp1983]

Just remember that if you use amps then they will always be powered up if you wire it like that, killed my battery on my bora cause I had a HU in which did not use the ignition live. Slowly drained it because the amp thought the radio was on (unless you wire your amps to the ignition live rather than the radio remote turn on wire of course)

[Bushboy]

Must have been the HU.  Whenever ive wired them to the HU remote wire, the amps turn on and off with the HU regardless of whether the ignition remains on or not.  The HU shouldnt still be telling the amps its turned on when its not 

[rubjonny]

yellow with white is NOT ignition live, its speed sensitive volume adjustment, done nothing on 99% of headunits
I believe this was part of the expensive aktiv speaker system, either that or VW supplied headunits make use of it.

As for ign live only the very late MK2s got it, they had a red/brown 'key in ignition' feed
Any 90spec MK2 can have this retro fitted, you have to add the missing pin into the ignition switch plug (Pin 'S' or 'SU') and run it to the headunit.
On a pre-90 MK2 ign live is easy to set up, drop the fusebox and you'll see 2 groups of spare spade connectors, one side live, the other ignition live.  Run a wire from there, but check the spades with a multimeter as some are not hooked up