Citroen Relay D+ Connection

dewierwan

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Hey everyone! I'm currently converting a 2017 Citroen Relay into a campervan, and I'm hoping to use a battery to battery charger. Does anyone know of a good place to find the D+ wire, or a wire that only has 12V+ when the alternator is charging the battery? I'm also pretty confused about which wire that comes out of the alternator is the D+, and have a preference for not connecting the b2b wire in the engine bay. Thanks!
 
Hey everyone! I'm currently converting a 2017 Citroen Relay into a campervan, and I'm hoping to use a battery to battery charger. Does anyone know of a good place to find the D+ wire, or a wire that only has 12V+ when the alternator is charging the battery? I'm also pretty confused about which wire that comes out of the alternator is the D+, and have a preference for not connecting the b2b wire in the engine bay. Thanks!
Hi and welcome to the forum..
i cant help with your specific van..but ill make one or two points i picked up working on a ford..
Firstly you won't want to be taking the d+ signal direct from the alternator...it will be a smart alternator most likely and usually they tell you not to do that ..its a hang over from the days when you could tap into the field coil winding on a conventional alternator..
A d+ signal is now usually a product of the electronics of the body control system and can include not just alternator voltage..but engine speed and say ignition..
On a ford they make a ground switching wire available as an engine run signal.. ie it switches to ground when the right conditions are all met...it is loosely taped into a wiring loom and easily accessed... I got that information from a converters manual on the ford etis site.. maybe Citroën supply similar information... that wire is capable of switching a relay coil ..the relay can be supplied with a 12v feed which becomes in effect the engine run signal for powered devices that need it..
Some of that may help but in any case it will bump your thread and someone familiar with a Citroën may be able to be more specific
Andy..
 
The easiest place i found on my 2016 relay van to get an ignition feed is from the back of the cigarette lighter socket. You can then use this as a trigger for a charge relay to engage the hab batteries. BUT the voltage on these vans is not that great. I would like to see 14.6v for a decent charge but mine is fixed 14.1v on the van battery will end up around 13.8v at the back of the van and the hab batteries wont charge very well without a B2B. If you got a smart alternator with stop start you need a special B2B that can handle huge voltage swings from 12.8v up to 15.5v.
BTW these vans are plagued with bad earths and wiring faults. The gearbox earth strap should be replaced the next time you go under the van if its over 3 years old.. If you don't get a solid 14+ volts on the battery you need to add another earth from the chassis jump start point down to the engine hoist loop. When i did this i found this earth actually supplied 40+ amps on idle tasking my brand new AGM starter battery from 13.7 to 14.1v So the factory gearbox earthpoint is NOT a good earth even with a brand new strap and clean contacts.
 
If you got a smart alternator with stop start you need a special B2B that can handle huge voltage swings from 12.8v up to 15.5v.
This is why you need D+ control, voltage control will send it scatty. I had no problems with my Votronic B2B when I had a smart alternator.
 
This is why you need D+ control, voltage control will send it scatty. I had no problems with my Votronic B2B when I had a smart alternator.
Hi, I've got a Votronic b2b too. Where did you tap into your vehicles D+ wire/terminal? Struggling to find out any info on line. My vehicle is a 2017 Citroen Relay. Cheers

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Hi, I've got a Votronic b2b too. Where did you tap into your vehicles D+ wire/terminal? Struggling to find out any info on line. My vehicle is a 2017 Citroen Relay. Cheers
Not sure about your vehicle. The motorhome 12V distribution box will probably have a D+ connection to trigger 12V fridge operation when the engine is running. My Carthago (CBE DS) and the Hymer (EBL) I previously owned both have a D+ connection. The D+ feed will originate at the alternator or ECU but it is probably easier to pick it up from the domestic wiring. My CBE DS300 has a simulated D+ output which I use.
 
Not sure about your vehicle. The motorhome 12V distribution box will probably have a D+ connection to trigger 12V fridge operation when the engine is running. My Carthago (CBE DS) and the Hymer (EBL) I previously owned both have a D+ connection. The D+ feed will originate at the alternator or ECU but it is probably easier to pick it up from the domestic wiring. My CBE DS300 has a simulated D+ output which I use.
Thanks for your reply. I actually have a standard van conversion so it does not come with a connection box for d+. I imagine I'll have to work it out from the alternator, tap in direct or trace to fuse. Apparently it's not that easy to locate and there is very little info on the Web.
Thanks
 
try inside the driverside door pillar beside the seat there is some wiring in there which usually has a d plus signal;
 
try inside the driverside door pillar beside the seat there is some wiring in there which usually has a d plus signal;
Thanks. I hear this is an extra for vans destined for the professional conversion market but standard panel vans don't have it. I'll have a good look this weekend to confirm .. One way or the other I'll find a way to link up to the d+, still expecting to have a dirty awkward hunt around the alternator and splicing in direct ish. Cheers
 
Done the same on 8 Ducato/Boxer/Relays, 2010-2020 (y)

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I am making a leap of presumption here, but as the relay and ducato are the same, there should be a connector behind the drivers seat RHD by the seatbelt mount specifically for converters. It contains the D+ and other essential wires
 
Thanks. I hear this is an extra for vans destined for the professional conversion market but standard panel vans don't have it. I'll have a good look this weekend to confirm .. One way or the other I'll find a way to link up to the d+, still expecting to have a dirty awkward hunt around the alternator and splicing in direct ish. Cheers
It was (and still is!) present on my self-build 2014 Relay. I was able to make the battery-to-battery link via a heavy duty terminal there and D+ is among the several signal connections available.
 
Thanks, yeh i'd seen this video but is it the D+ or just the ignition wire? My b2b needs to directly sense the alternator is generating power and not just that there is power from the battery. Or maybe this is a workaround? Cheers
Done the same on 8 Ducato/Boxer/Relays, 2010-2020 (y)
 
Thanks, yeh i'd seen this video but is it the D+ or just the ignition wire? My b2b needs to directly sense the alternator is generating power and not just that there is power from the battery. Or maybe this is a wirkarounf Cheers
Done the same on 8 Ducato/Boxer/Relays, 2010-2020 (y)

I t
I am making a leap of presumption here, but as the relay and ducato are the same, there should be a connector behind the drivers seat RHD by the seatbelt mount specifically for converters. It contains the D+ and other essential wires
Yeh they both have these for converters but as mine was a designated as a panel van it does not come with it 😭

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Thanks, yeh i'd seen this video but is it the D+ or just the ignition wire? My b2b needs to directly sense the alternator is generating power and not just that there is power from the battery. Or maybe this is a workaround? Cheers
If you have a Votronic, I've wired 2x the little 30a one, a 60/40/430 triple, and my current 90a VCC. All have worked perfectly using this method. Not tried it on a van with Start/Stop yet, but doing one later this week.

Edit: Just in case you didn't know, the guy who made that video was the installer for NuVenture at the time.
 
if you cant find one or its difficult there is a work around use a smartcom relay tto sense voltage on any live feed and then use the signal from that to switch a dumb relay that is your split charge, if your running a 3 way fridge you can use the smartcom to run that as well the van i built ran like that for 5 years till i got rid of it some build details in blog on signature below
 
If you have a Votronic, I've wired 2x the little 30a one, a 60/40/430 triple, and my current 90a VCC. All have worked perfectly using this method. Not tried it on a van with Start/Stop yet, but doing one later this week.

Edit: Just in case you didn't know, the guy who made that video was the installer for NuVenture at the time.
i thought with stop start you had to use a b2b not a split charge?
 
sorry should have said you set the smartcom to above battery votage so it only switches when the van is running rather than just ignition the smartcom has an adjuster for the voltage it switches at if you google smartcom realays youll find a lot of bad reviews but thats because people thing they can use that alone as a split charge and they are not up to it. but using it just to trigger a dumb relay is very little load and they are more than capable using it to switch a b2b on will be no problem
 
Thanks, yeh i'd seen this video but is it the D+ or just the ignition wire? My b2b needs to directly sense the alternator is generating power and not just that there is power from the battery. Or maybe this is a wirkarounf Cheers

I t

Yeh they both have these for converters but as mine was a designated as a panel van it does not come with it 😭
They don't make different looms for different customers and the connectors are just taped up and not used on some models. The wiring layout of the base vehicle is the same in a motorhome, a builders van or a pickup truck. It is the same with dashboard lights, all the options are there but not all used

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...
On a ford they make a ground switching wire available as an engine run signal.. ie it switches to ground when the right conditions are all met...it is loosely taped into a wiring loom and easily accessed... I got that information from a converters manual on the ford etis site.. maybe Citroën supply similar information... that wire is capable of switching a relay coil ..the relay can be supplied with a 12v feed which becomes in effect the engine run signal for powered devices that need it..
Hi Andy,

Thanks for the great info about the Ford Transit's ground switching wire, for use with a relay. I found the wire easily on my 2013 Mk7 but I am struggling to make use of it!

Are you able to tell me the specification of the relay I should use (I guess Make & Break, Normally Open??) and some more tips on the wiring?

Thanks in advance!
 
but I am struggling to make use of it!
hi... as long as you understand what it actually does then it should be fairly straight fwd... it simply switches a path to ground when the all the following conditions are met..ie..ignition is on , the engine is running at or above 800rpm , and the alternator voltage is above a certain level..
to use that wire you would simply supply a relay coil with 12 volts and the other side of the coil would be connected to the ground switching wire.. then a normally open relay supplied with 12 volts would close and provide you with effectively a 12v engine run power supply for use as you want..
the supply switched by the relay and its capacity will depend on what items you intend connecting to the engine run supply
hope thats clear
Andy
 
I figured it out, nothing too tricky really!
 
hi... as long as you understand what it actually does then it should be fairly straight fwd... it simply switches a path to ground when the all the following conditions are met..ie..ignition is on , the engine is running at or above 800rpm , and the alternator voltage is above a certain level..
to use that wire you would simply supply a relay coil with 12 volts and the other side of the coil would be connected to the ground switching wire.. then a normally open relay supplied with 12 volts would close and provide you with effectively a 12v engine run power supply for use as you want..
the supply switched by the relay and its capacity will depend on what items you intend connecting to the engine run supply
hope thats clear
Andy
Oh, just saw your response, yes, thanks anyway!
 
I drew a circuit diagram of my final setup - i.e. to obtain a positive signal when the engine is running so the EZA MBB50 DC-DC charger knows to initiate the charging of the LiFePO4 from the starter battery.

Enjoy ::bigsmile:

IMG_20210322_115443278_2.jpg

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I drew a circuit diagram of my final setup - i.e. to obtain a positive signal when the engine is running so the EZA MBB50 DC-DC charger knows to initiate the charging of the LiFePO4 from the starter battery.

Enjoy ::bigsmile:

View attachment 475923
Hi Vorlic. As your diagram says, "stay sane". Like you, I'm struggling with this D+ stuff. I have a Mk8 with Renogy B2B and I've piggybacked a feed from an ignition live fuse. It seems to work, but I think it's wrong. Have you a link for the relay? This might be the answer assuming the Mk8 has the glovebox lead.
 
If you get a smartcom relay from ebay you can use that with the feed you have now from the lighter
The smartcom is adjustable set it to over 13v and it will become your dplus signal
 
How is it wired? And will it be wired to a permanent live? Or the switched live I'm currently using?
It will obviously be different to Vorlic's diagram.
It's as I said before, it's OK saying use this or using that, but how do you wire the damned thing?
 

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