Nissan Frontier Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
544 Posts
Discussion Starter #1
Has anyone ever noticed the voltage fluctuate between 14.4 and 13.3 volts for no discernible reason? As I run an OBD Reader app on my phone I've got a digital display of the voltage and while driving along for no notable reason the voltage will drop from 14.4 down to 13.3 volts for several minutes and then again return to the normal voltage. I can also see this in the dash mounted gauge in that normally the needle points to the top right of the little battery icon or closest to the (+) symbol to which when I notice this voltage drop on the app if I look at the dash gauge the needle will be closer to the (-) symbol... Not worried but just find it curious as to what's going on within the truck that makes for a full 1.1 volt drop...
 

·
Registered
Joined
·
354 Posts
Same here. I installed a digital volt meter in the empty 4 wheel drive selector blank and I've
noticed that it will jump from 14.3---4V to 13.1...2V for no reason I can see. Sometimes the
A/C is running, sometimes not. Sometimes the headlights and or wipers are on, sometimes
not.

I guess it knows what it's doing, everything works as it should.
 

·
Admin
Joined
·
3,280 Posts
I monitored today for about a 1/2 hour during a mix of idling in drive and highway driving, but it never went outside the range of 13.9-14.2. If I remember I'll monitor again tonight as it will be dark and raining with some more electrical load.

Screenshot_2017-03-09-15-40-31.jpg
 

·
Registered
Joined
·
544 Posts
Discussion Starter #6
I just find it curious as I do a lot of boring interstate driving with the cruise control on, even tried turning stuff on/off when I notice the drop and can't quite put a finger on the cause...
 

·
Premium Member
Joined
·
505 Posts
As stated above gen 2 frontiers detect amount of current drain and adjust voltage as needed. If you look at ground return lead to battery you will see that it passes thru a ring that measures current.
 

·
Admin
Joined
·
3,280 Posts
I think the OP understands that the current drain will be detected and voltage adjusted accordingly based on requirements, but I noticed the same symptoms tonight on a long drive on cruise control with no changes in electrical load. I did not notice this earlier today during city driving and idling.

The change from 13ish volts to 14ish volts and back to 13ish volts is very dramatic (within seconds) and it seems like it should be more gradual. For me, it was 13ish volts for 5 minutes, then 14 ish volts for 20minutes, then 13 ish volts for 10 mintues.

I doubt this will ever cause any issues, but it is certainly interesting.

I think we need our posting god @smj999smj to answer if this occurs in his R51 pathfinder and to provide an explanation :)
 

·
Registered
Joined
·
354 Posts
I think the OP understands that the current drain will be detected and voltage adjusted accordingly based on requirements, but I noticed the same symptoms tonight on a long drive on cruise control with no changes in electrical load. I did not notice this earlier today during city driving and idling.

The change from 13ish volts to 14ish volts and back to 13ish volts is very dramatic (within seconds) and it seems like it should be more gradual. For me, it was 13ish volts for 5 minutes, then 14 ish volts for 20minutes, then 13 ish volts for 10 mintues.

I doubt this will ever cause any issues, but it is certainly interesting.

I think we need our posting god @smj999smj to answer if this occurs in his R51 pathfinder and to provide an explanation :)


That's just silly. It's an electronicly controled system. It doesn't think...
well it's time to increase the charge on the battery, but I don't want to
scare the driver (who shouldn't be monitering this anyway, that's why there's
no digital volt meter installed in the first place), so I'd better increase
the charge rate very slowly.

You need to learn how your truck works and accept it. rather than thinking
" Hey that's not the way I (who know nothing about these sort of things)
think it should work, therefor it must be wrong. ::wink::
 

·
Super Moderator
Joined
·
3,188 Posts
The ECM monitors the voltage sensor on the ground cable and uses this info to control the alternator output, which, in essence, decreases the load on the engine by reducing the workload on the alternator when it isn't needed. This will account for the fluctuation in charging system voltage. That said, I agree totally with Hotrod's comment: "This is being over thought. The system is working correctly. End of story."
 
1 - 12 of 12 Posts
Top