Ignition only wire under the bonnet?

[drivesafe]

Hi folks and I’m hoping someone can help a customer of mine.

He is fitting a separate power supply cable from the cranking battery in his D3, to the 3 way fridge in his caravan.

This power supply needs to be switched on and off with the ignition ( or if available by a wire only powered when the motor is actually running ).

Does any body know of the location and colour of a wire, preferably under the bonnet, that can be used to activate a relay, to control the power supply going to the fridge.

Any help would be appreciated.

[rovers4]

Hi,
A few ideas:
I would be powering the van fridge from the alternator output. Yes this could come from the main battery, but consider which location is easiest to work with.
The circuit should be fused, or have an automatic re-setting cct breaker, of course.
The circuit should be controlled by a relay, which is itself triggered by the "ignition" feed or something fed with such.
There should be a manual switch in this trigger to the relay.
The switch should be in the cabin.
The feed can therefore be picked up in the cabin.
As the relay trigger circuit is low in current draw, it can come from an "ignition" fed accessory - wipers, aircon, mirrors or the feed that triggers the headlights the same way when Ign comes on.
The trigger wire itself should be fused where it comes off the standard wiring.
There will still be a need to pass the now "fused and switched" feed out through the firewall to the relay. Can be a low duty wire, but give it double protection going through the firewall.

All this is basic, but it sometimes helps to see it in print and coming from someone else.

Does this make it any easier?

Rovers4.

[sniegy]

Tim,
In front of the battery tray in the D3/D4 are a couple of connectors. They are for the Fuel Burning Heater (FBH) in which Australia does not have.
I dont have the wiring diagrams in front of me (i have been home for a while due to accidentially poisining myself:eek::eek::mad:...dont ask , it will hurt you when u stop laughing..) at the moment but someone with access may be able to find out what turns on & when etc etc..
I will check on mine tomorrow morning when i stop going to the lav'.:(

Cheers.

[CaverD3]

There is definately one in the headlight switch, large red connection.

[discomaniac]

Hi,
Is there a problem with just using the "Fridge" pin on the "S-type" power socket in that "other" seven pin plug at the rear of the car. There seems to be an "Ignition On" pin as well as "Fridge" pin to power the fridge when ignition is on and a "Constant 12v" pin for connecting caravan lights/battery.

Or is this not connected in Australia or maybe the wires not large enough to power our bigger caravan fridges.

Just a thought.

discomaniac

[ken224]

The switched +12V in the 'S' socket (pin 4, return on pin 3) is protected by a 15A fuse. Probably not enough (how much current does the fridge need?)

The permanent +12V (pin 6, return on pin 7) has a 30A fuse. Not really suitable for the fridge though as it is permanently on.

This applies to D4. Not sure about D3, but can't be much different...

Does this help?

[sniegy]

Tim,
The 2.7L has only 2 connectors in front of the battery tray. One large connector with 2 wires (Black & Purple/Brown) Purple is pemanently live.
The other connector is the control wire & canbus network which are not active whatsoever.

I beleive from memory the 3.0L has another connector, hopefully someone else with a test light can help..sorry:(

[sniegy]

There is definately one in the headlight switch, large red connection.
Tim,
again CaverD3 has another good option,
The headlight switch pack is where we wire customers bluetooth phone kits from. In the head light switch, (The whole panel comes off including air vent) to reveal the connector. Brown/Green wire is permanent power, Brown/Purple (THIN WIRE) is ignition switched wire.
It is an easy task to run the wire throught the wiring grommet on the firewall if needed. hope this helps.

Cheers

[drivesafe]

Hi Folks and thanks for all the very useful feedback.

Sorry I have taken so long to reply, been flat out, but as soon as the rains stops, I’ll followup on the info supplied.

Again muchly appreciated.

Cheers, Tim.

[AndrewT49]

Pete,

Had a go at removing the cover over the light switch, but lost my nerve as didn't want to break anything. Is there a secret. Do you have to remove the light switch first, or does the cover lift off from the bottom?

Andrew

[CaverD3]

Same clips as most of the dash, you have to pull hard from the bottom the top is held in by lugs the bottom by clips.

[drivesafe]

Same clips as most of the dash, you have to pull hard from the bottom the top is held in by lugs the bottom by clips.

Didn’t happen without pics?

[CaverD3]

If you insist. :angel:

http://www.disco3.co.uk/gallery/albums/userpics/14227/normal_DSC_0354.JPG

https://www.aulro.com/afvb/images/imported/2010/10/824.jpg


https://www.aulro.com/afvb/images/imported/2010/10/825.jpg

[rufusking]

Dragging out an old thread but is most relevant to what I'm after and a lot of time has passed so hopefully someone has investigated things further.

Has anyone found an easy accessible ignition source under the bonnet, not looking for any major current just enough to pull in a relay (30mA).

[TDV6]

In the engine bay, I use the active leg of fuse 9 to get power that's only active with the engine is switched on. I use this to power daytime running lights, ?Navman GPS?, ?Scanguage II? and Engine Watchdog? gauges.

The connector to the fuse block is a Narva crimp on connector that I have cut one leg off then run to an in line fuse then on to my accessories.

Ryall

[Blknight.aus]

if its for a van...

isnt there an aux supply that does that already fitted down the back of the vehicle? why not just use that to trigger a relay down the back end of the vehicle?

even smarter why not do it via A VSR on the head of the relay so it wont come on unless the voltage is up and the ignition is on?

[Stuart02]

Might depend on whether you're pre or post 2010. It made a difference when wiring my DRLs (I put it in a thread somewhere). I was told to use the horn wiring of all things but that's active with the ignition, not just when the engine is actually running. That could be trickier?