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Large MPVs -- Ford Galaxy / VW Sharan / SEAT Alhambra: => Mk3 Ford Galaxy / Ford S-Max => Topic started by: grimroz on September 17, 2019, 09:45:15 PM

Title: Ignition-switched 12V supply location?
Post by: grimroz on September 17, 2019, 09:45:15 PM
Hi all, I've been struggling to find a suitable location to tap-off a fused 12v supply for a couple of low-power accessories located in the roof-mounted storage compartments. These only take less than 1A in total, so I'm looking for the most convenient location which can cope with this extra current where I can connect to by a scotchlock type of connector, and somewhere which doesn't involve stripping out half of the dashboard!   I was banking on the cigarette lighter being ignition-switch controlled but just found out that both front and rear 12v sockets are permanently connected to 12v.  -DOH!!!!!!   The connections to the roof-mounted lighting switches are permanent 12v too.  -would have been perfect if ignition-switched.   I imagine that gaining access to the ignition switch itself could be challenging.    Any suggestions would be really appreciated.  Thanks!
Title: Re: Ignition-switched 12V supply location?
Post by: SirDavidAlhambra on September 17, 2019, 10:13:57 PM
Firstly, my friend, welcome to the forum. I hope you make as many friends here as I have.

Secondly, have u considered tapping into the car stereo power supply? I think thatís the one most people tap into.

Or maybe the switch for the headlights main beam and then running it up the plastic trim which goes up to ze roof.

But please, think of the safety first above all. Must not overload the electrics or car will catch on fire.

Thank you
Title: Re: Ignition-switched 12V supply location?
Post by: johnnyroper on September 18, 2019, 12:53:57 AM
Firstly, my friend, welcome to the forum. I hope you make as many friends here as I have.

Secondly, have u considered tapping into the car stereo power supply? I think thatís the one most people tap into.

Or maybe the switch for the headlights main beam and then running it up the plastic trim which goes up to ze roof.

But please, think of the safety first above all. Must not overload the electrics or car will catch on fire.

Thank you

Thatís a bit extreme ainít it? Unless you are tapping off battery feed thatís not fuse protected then it wonít catch fire you would just run the risk of popping fuses.
As for an ignition feed a mark 3 I will assume has can bus so may not be possible to tap off the radio.  If you have a multimeter have a look in fuse box for an ignition feed and use a fuse tap to pick a feed up from there if itís a fairly accessible box inside the car.
Title: Re: Ignition-switched 12V supply location?
Post by: grimroz on September 18, 2019, 11:59:09 AM
Hi, many thanks for your suggestions.  I'll have a poke around the interior fuse box this afternoon to find a switched supply on a 15A or higher fuse. I'll then take a 5A in-line fused tap off and route to the roof storage pods via the pillars.  No doubt what seems to be a simple task will be challenging to say the least!
I tried to fit a rear reversing camera which is linked to the head unit via 2.4Ghz RF link, but I've found that there is so much electronic interference around the dash that the signal is comprehensively zapped.  Has anyone else had this problem?    Now going to settle for a cabled feed to the head unit, though the routing looks to be a huge amount of fun. . . .
But first, fitting new type 110 battery as the old one was regularly settling down at 11.0v  so way past it's prime. (I know the feeling well)

Cheers!
Title: Re: Ignition-switched 12V supply location?
Post by: SirDavidAlhambra on September 18, 2019, 01:53:27 PM
I love car batteries, it's one of my favourite topics. I always put in my car the very biggest car battery I can find. Also I like using branded ones like Varta. Once every year I use my car charger to 'recondition' the battery.

Also although it's hassle to put the wire down the truth is u just can't beat a wired connection for something like a camera.

It sounds like you have a fun project going on there, please do post pics once it's all done!

 [FUN]
Title: Re: Ignition-switched 12V supply location?
Post by: brianh on September 18, 2019, 03:54:49 PM
The fuse taps are a better way of doing it - thats how most dashcam hardwire units work. Some cable threading rods (or something rigid enough like a net curtain rod) may help to route it above the roof, once you get to there most of the time you can route it down via the inside edge of the door rubbers or behind bits of trim.
Title: Re: Ignition-switched 12V supply location?
Post by: mike wilson on September 20, 2019, 09:51:24 AM
I think you'll find that the front lighter socket _is_ ignition connected but with a time delay of about 15 minutes for switching off.  Or maybe that's BCM connected.  The joys of the Canbus system.....
Title: Re: Ignition-switched 12V supply location?
Post by: mike wilson on September 20, 2019, 09:54:04 AM
I tried to fit a rear reversing camera which is linked to the head unit via 2.4Ghz RF link, but I've found that there is so much electronic interference around the dash that the signal is comprehensively zapped.

Non standard head unit?  That would be my first suspect.
Title: Re: Ignition-switched 12V supply location?
Post by: mike wilson on September 20, 2019, 09:57:22 AM
p.s. If this vehicle is new to you, you need definitive proof that both timing belts have been changed before 125,000 miles.  Many, many tales of the internal one snapping well before the recommended (max) interval because they don't realise it's there or think it is a chain.
Title: Re: Ignition-switched 12V supply location?
Post by: SirDavidAlhambra on September 21, 2019, 08:27:55 AM
Yeah, lots of people say these jobs have been done when they havenít.

I once took a car to a dealer for a service and they didnít even change the oil but acted all official and expensive