Nissan D40 Navara Alternator question

Submitted: Saturday, Aug 19, 2017 at 21:16
ThreadID: 135427 Views:13202 Replies:3 FollowUps:6
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Hi All,

My son has a 2013 Nissan Navara D40 diesel duel cab (Spanish model) and is in the process of installing a second battery in the tub (for fridge etc.) the battery pack he is installing includes a 120 Amp/Hr AGM and a Projecta 25 amp 3 stage DC/Solar charger.

We have connected the system to the main start battery, plugged the fridge in and started the vehicle to check the operation of the system - all working well with the Navara start battery charging at around 14.5 vdc. we then turned the Navara off and let the fridge run for while on the aux battery - all good. Then started the Navara again and the Projecta charger would not kick in - Starter battery alternator output was only 13.12 vdc - which is slightly low to activate the Projector charger at 13.2 vdc. Now according to the Projector manual for the 'smart alternators' you need to connect the 'blue cable' to the vehicles ignition to allow it to operate from a lower set voltage of 12.2 vdc.

This is understandable however running another cable from the tub back into the cab (and to locate the ignition wire) is going to be a pain!

What I would like to know is how can the 'smart alternator' be modified to act like a normal alternator? I have researched the net and found that if a GREEN wire is removed from the cable connection in the terminal/fuse box located behind the start battery the alternator will revert back a normal operational alternator which will allow the Projector DC charger to work as it should, I have located this GREEN cable but was unable to remove it from the connector without fear of damaging it and need to confirm if this is the correct cable to remove?

Many thanks


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Reply By: IvanTheTerrible - Saturday, Aug 19, 2017 at 21:54

Saturday, Aug 19, 2017 at 21:54
A diode mod will lift it by about 0.6 volts which should be enough to work the Dc-Dc
AnswerID: 613193

Follow Up By: RMD - Sunday, Aug 20, 2017 at 08:25

Sunday, Aug 20, 2017 at 08:25
Possibly NOT if the ECUis doing the control of the regulator field current to the rotor.
FollowupID: 883583

Reply By: Ozhumvee - Sunday, Aug 20, 2017 at 07:15

Sunday, Aug 20, 2017 at 07:15
Rather than remove the cable from the connector why not just cut the wire back where it is easier to access, then it can be easily reconnected by soldering or connectors if necessary.
AnswerID: 613197

Reply By: Member - Andy M (QLD) - Sunday, Aug 20, 2017 at 07:59

Sunday, Aug 20, 2017 at 07:59
An easier fix is to just unplug the small black plug at the bottom of the battery current sensor at the negative terminal of the battery. That makes the alternator behave like a normal alternator apparently as it's not getting the message to reduce the voltage. I did this on the recommendation of another guy who had no issues over 18 months and I also have not had any problem over about two years now. Always getting at least 14.1 volts.
You can plug it back in again before service time if you want to or if you are not needing to run the fridge and charge your second battery. I just taped up the removed plug to keep it clean.
AnswerID: 613198

Follow Up By: Member - Howard P (WA) - Sunday, Aug 20, 2017 at 15:22

Sunday, Aug 20, 2017 at 15:22
Hi Andy,

Thanks for the info, my son's ute doesn't appear to have this 'black plug' on the neg side of the start battery - see photos of his set up -

So not sure of where to go now as there is no black plug but a grey connector plug on the neg side of his battery, is this set up similar to the one you mention in your reply? and would this be the plug - it has 4 wires going into it.


FollowupID: 883592

Follow Up By: Member - Andy M (QLD) - Sunday, Aug 20, 2017 at 16:43

Sunday, Aug 20, 2017 at 16:43
Sorry Howard, yes that is the one to remove. I've had mine taped up with black tape so was thinking black. Just uncovered it and it is grey, the same as in your photo with four wires into it. That's apparently just measuring the current at the battery and sends a message to the ECM etc to help it decide whether to change the charging voltage. If its not getting the message it behaves as a normal alternator.

It's a bit of a mongrel to undo but just depress the bottom wide part of the plug as in your second picture and give it a bit of a wiggle and it should come out.

Also recently found a website that has a link to the Australian D40s workshop manual. Can't seem to download it but you can read the pdf files ok. I'll try and put in the link.. Just click on the Spanish one if that is your son's.
The charging system is described in the SC.pdf file.

Link to Australian D40 workshop manuals etc


FollowupID: 883593

Follow Up By: Member - Howard P (WA) - Sunday, Aug 20, 2017 at 16:59

Sunday, Aug 20, 2017 at 16:59
Many thanks Andy,

We will give it go this afternoon and let you know how it goes :)

Also have downloaded the link for the manual and will check that out tonight.

Thanks again


FollowupID: 883594

Follow Up By: Member - Howard P (WA) - Sunday, Aug 20, 2017 at 20:34

Sunday, Aug 20, 2017 at 20:34
Hi Andy,

Thanks mate, all good now. Removed the plug and went for test drive, alternator output now reading 14.3 vdc as opposed to yesterday after the same run where it went down to 13.1 vdc.

The young bloke says he owes you a beer - next time he is in QLD


FollowupID: 883611

Follow Up By: Member - Andy M (QLD) - Monday, Aug 21, 2017 at 08:29

Monday, Aug 21, 2017 at 08:29
Glad to know it worked out. I was thinking the reason my plug was getting a bit hard to get out might be because of sticky residue from the tape. If you tape it up it may pay to put a non-sticky layer first.
FollowupID: 883618

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