Mk7, D+ Engine on solution.

[Stav242]

On a Mk7 T350 LWB..
I was looking for the simplest option to get a D+ engine on signal for my MPPT charger which needs an alternator signal before it uses the vehicle battery to charge the leisure battery.

Thanks to someone... (I'll try to find the link) it was not so hard.

Behind the glovebox, there is a brown wire taped up to the wiring loom with an unconnected spade connector hanging loose.
This is becomes Ground when the alternator is running.

I took a wire from the fuse box with an ignition 12v through a 5A fuse.

Connect both of these to a relay coil, and then connect the of Ingition 12v through the relay switch so a pin becomes 12v when the relay switches on.

Then connect this to the MPTT charge controller.

Now charging only happens when the engine is running.

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[Airthies]

It's surprising how few people know this is there.
Nice to see things being done properly

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[Stav242]

Apart from me soldering a fuse to the board... Better than no fuse tho.

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[Airthies]

Apart from me soldering a fuse to the board... Better than no fuse tho.

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That's not an issue as long as you don't have to keep changing the fuse



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[jschuld]

Thank you sir!

I have read about this but have somehow not been able to locate this wire. Your photo pointed me in the right direction. Do you have any idea how much current you can sink through that signal? I'd like to switch a battery isolation relay with it.

Cheers
Johan

[jschuld]

Ok.. answered my own question 200mA. (https://www.manualslib.com/manual/83125 ... 132#manual)

[Airthies]

Ok.. answered my own question 200mA. (https://www.manualslib.com/manual/83125 ... 132#manual)

You can download the complete BEMM PDF and more from ford website too

https://www.etis.ford.com/bemm/bemmAcce ... epted=true

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[Samwise-zambeezi]

Hi guys,

I'm trying to find best way to link a HD relay to the alternator D+ feed for split charging (can't use a VSR as, apparently, they sense current from solar panels) and just noticed this post.

I must admit, I didn't follow what you did entirely (I'm a complete noob just researching and learning at the moment) but wondered if I might be able to use that same cable plug for my relay? Is it linked to D+ on the alternator? And do you know if it's the same on mk6s?

Thanks, sam

[Samwise-zambeezi]

... Ah. Just read jschuld's link to the manual and read it's only on 2006 onwards! Not mine then, being a mk6, damn!

[Kwiks1lver]

Hi @Stav242 - thanks for starting this thread - it seems to be a good start for what I'm trying to do, though I could use a bit of extra help with it!

I'm looking to install a 40A DC-DC charger (https://uk.renogy.com/12v-40a-dc-to-dc-on-board-battery-charger/) from Renogy and am just wondering if there'd be a way to run this via the CCP instead of going via the glove box fuses as you've done.

For example, I've connected a GPS tracker via the CCP and this is able to detect the 'spike' from the starter battery in order to send me the notification that the engine has been turned on. I'm trying to figure out if there's some way of using this 'spike' to send the signal to the DC-DC charger that it's good to turn on and start charging.

A second question which has since come up is that I was planning on using the CCP to grab the power for the P+ on the charger (as it's already fused), but I've since read that it might be better to go directly from the battery so that I can also terminate the circuit on the negative of the battery. Are there any opinions out there on this, and if the latter option is better, which battery should I directly connect to, given that there are two of them?

For reference, I've got a 2013 Mk7 with dual-starter batteries.

[johnporter11]

Hi Quicksilver. I'm in a similar situation to yourself. I've actually bought the 40w Renogen, but not yet fitted. I'm also waiting for all my connection leads. I'm taking my positive feed from the rear battery (the one at the back of the driver's seat), but haven't yet decided where to find the ignition live.
Now, the plot thickens. I may be wrong, but I believe both batteries are not "starter batteries". One is a starter battery, and one is an auxiliary. And I'm beginning to think the rear one is the auxiliary battery. I measured the voltage on it today and it was less than 12v (!). But the van starts fine. I guess with it not being used for over a week, and the side step being activated frequently, the auxiliary battery's been taking a hammering.
But this begs the question, should I be connecting the Renogen to the starter battery or the auxiliary battery? I believe the two vehicle batteries join up in parallel a few seconds after start up, so maybe it doesn't matter? And of course if the alternator has to look after my weak auxiliary battery it may take a wee while for the DCDC charging to kick in.
And my other question is, should I be connecting my negative cables to the battery negative - or to the vehicle ground, e.g. the handbrake bracket nut.

[workbox]

mk8 transit,
Under steering wheel fuse box I found empty fuse slot that goes live when I turn key on.
However I bought new B2B charger Victron Orion and was very impress. Requires nothing. Simply leisure battery and starter battery connection.
Detects automatically when engine start up.

Typically components is earthed to the vehicle body, which is earthed to the negative (-) terminal of the battery

[Airthies]

If your going to use the hand brake bolt as an earth point you might as well poke it onto the battery bay and connect to one of the M6 studs on the earth leads of the battery earth clamps.

The two batteries under the seat tend to be front "aux" & rear "start"

If your not sure, and do have the radio code, try disconnecting rear battery then front battery and see which one turns off cab lights etc.
Also g as you've not had key in ignition at the time

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[workbox]

If your going to use the hand brake bolt as an earth point you might as well poke it onto the battery bay and connect to one of the M6 studs on the earth leads of the battery earth clamps.

for newer vehicles with smart alternator I would connect to vehicle body/chassis to by pass sensor that goes after negative battery terminal.
Watch this video
https://www.youtube.com/watch?v=pOs7p-InF2o

[Airthies]

If your going to use the hand brake bolt as an earth point you might as well poke it onto the battery bay and connect to one of the M6 studs on the earth leads of the battery earth clamps.

for newer vehicles with smart alternator I would connect to vehicle body/chassis to by pass sensor that goes after negative battery terminal.
Watch this video
https://www.youtube.com/watch?v=pOs7p-InF2o

But on the transit post 2012 afaiaa the Mk7 has a mount bolt" on the chassais side of the smart sensor.

As marked by the big red arrow in the picture. Freshly stolen from another thread.


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