Switched live without ignition ON but the vehicle is unlocked

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shark
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Joined: Wed Mar 25, 2020 10:59 pm
Engine size/power: 1.6 16V Petrol (100bhp)

Switched live without ignition ON but the vehicle is unlocked

Post by shark »

I am using a phone holder in my Caddy 1.6 2009 which has automatic locking and rotating with wireless charging. I attached it to ignition switched source in the fuse box.

When I turn on the ignition, the phone holder is powered and opens the clamping arms. After that I could put my phone into the holder and it closes the arms automatically. Sometimes it takes time, it would be more convenient if it opens those when I open my car by key and the interior lights turn on.

I checked the wiring diagram and I did not find this kind of switched power which is switched on before ignition ON but it is disconnected from the battery after I lock the car.

Judging by the Touareg electronic system J689 (Terminal 30) is responsible for this behavior. But I did not find any way to have a direct, fixed connections to the switch live, it is the integrated part of J519.

Do you have any infos, idea regarding to this? I was thinking about it and maybe I could use fixed light power feeding a relay and swich direct power from the battery.
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philsparky
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Re: Switched live without ignition ON but the vehicle is unlocked

Post by philsparky »

Ideally you want to tap into the drivers door open/closed detection switch before it enters the door control module, have that trigger a timed relay to give you time to get the ignition running, then use the loss of 12v when you turn the ignition off to deactivate power to the cradle.

Terminal 30 is usually 12v permanently and I'm pretty sure the interior light behavior is controlled via the earth coming from the bcm.
2017 Caddy Trendline 2.0TDI 102ps, Reflex Silver
shark
Caddy2k Groupie
Posts: 10
Joined: Wed Mar 25, 2020 10:59 pm
Engine size/power: 1.6 16V Petrol (100bhp)

Re: Switched live without ignition ON but the vehicle is unlocked

Post by shark »

Thank you for your reply.

When I unlock my car (without opening the door), the internal light is on and J689 relay is activated. If I remove the relay, the internal light switches off. It is also off after 10 minutes I lock my car and the relay is also deactivated.
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philsparky
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Re: Switched live without ignition ON but the vehicle is unlocked

Post by philsparky »

according to the schematic j689 is the permanent 12v supply for a lot of systems, this would explain why your lights go out if you remove it, the schematic shows the blue/grey wire coming from j519 controls when your interior light(w1) comes on.
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2017 Caddy Trendline 2.0TDI 102ps, Reflex Silver
shark
Caddy2k Groupie
Posts: 10
Joined: Wed Mar 25, 2020 10:59 pm
Engine size/power: 1.6 16V Petrol (100bhp)

Re: Switched live without ignition ON but the vehicle is unlocked

Post by shark »

Finally, I installed a 449 relay and the K10 terminal of J519 controls the relay. It behaves as I expected. BTW, as I suspected, K10 terminal has a direct (0 ohm) connection to switched contact of J689. Thanks a lot.
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