Electrical Questions and Fuse Identification

[StevieB]

Hi everyone, I'm new here. I have a 2012 Navara D40 that I'm gradually learning how to tinker with. I'm currently looking at the electrics, having had a couple of issues that might be connected:

1) Glow Plug Relay Fault (P0380) - I've since replaced the relay and all 4 glow plugs and the light hasn't come back on
2) Dead Battery - Wouldn't hold enough charge overnight to start the next day despite only being 3 years old. Now replaced with a new one and I did wonder if the above issue was contributing to battery drain

In trying to solve these problems I've discovered that I have a small (130mA) draw when the car is off, locked and has powered down (draws 210mA while it's powering down for about 3 mins). I don't know if this is normal or excessive or indeed enough to have completely killed the battery? The alternator seems to be OK and charges the battery at 14.2V when the car is started. While I was looking for a source of the drain I noticed two things that I wondered if you could help with:

1) I have a single wire coming from the battery positive terminal that goes through a 25A fuse and then off across to a bundle on the right hand wing of the engine compartment. Where the old battery sulphated, it has corroded the fuse holder for this circuit. I've attached two pictures to show the fuse holder and the bundle on the right of the engine bay. Does anyone know what this might do and how to go about replacing the fuse holder?
2) The truck has a snugtop and I noticed that its internal lamp is no longer working. Does anyone know where the fuse is located for this circuit? Is it part of the 'Room Lamp' circuit?

Any pointers would be much appreciated. Is there anything else I should be considering when looking for the source of the drain?
Cheers,
Steve

 

[Old.Tony]

Your car's Body Control Module (BCM) will draw power constantly for two reasons - first, it "listens" for the remote control being used to unlock the doors, and second for the anti theft system.

I have a large Century battery in mine, the biggest that fits in the tray, and it was going flat after about 6 days. For some time now, the car's worn a 40W solar panel on the roof with a cheap PWM charge control module that is disconnected from the system when accessories are turned on (just a simple relay). I haven't had any battery problems since I put this in.

The fuse holder looks like a generic one you could buy in Jaycar. I have a similar one in mine, installed by the dealer for the driving lights I had added to the car when new.

 

[StevieB]

Ah, OK. Would you say that something around 100-130mA is normal for this truck then? Any tips on how to work out what that fuse is supplying? Is it standard, I've not modded in any way and I don't think the previous owner did apart from the Snugtop.

Thanks for taking the time to answer,
Steve

 

[Old.Tony]

Apart from physically following the wire, not really. Did the thing have driving lights that are no longer there? Removing the fuse won't do a thing. The entire harness may have been removed with the lights, especially if they had an expensive set of lights they were happy with.

 

[OldManBeard]

The simplest way to find out what the fuse is for is to find out what doesn't work when the fuse is not there. It's a whole lot easier than trying to trace the wiring on these machines. I started my working life as an electrician and have been working with car and bike electrics for a long time, yet I'm still struggling to work out some of the wiring on my Navara. The complete lack of relevant and accurate wiring diagrams doesn't help.

 

[StevieB]

The simplest way to find out what the fuse is for is to find out what doesn't work when the fuse is not there. It's a whole lot easier than trying to trace the wiring on these machines. I started my working life as an electrician and have been working with car and bike electrics for a long time, yet I'm still struggling to work out some of the wiring on my Navara. The complete lack of relevant and accurate wiring diagrams doesn't help.

Looking at the state of the fuse holder I imagine it stopped working long before I pulled the fuse, which suggests it's something that I don't use or notice. Maybe the tow bar electrics? Would they have a separate live feed and a 25A fuse?
Cheers,
Steve

 

[OldManBeard]

I'm tending to favour Tony's idea that it may be for driving light that have been removed. If you have 7 (or more) pins in your trailer socket, then it could be for auxiliary power for that. To test that possibility, with the ignition completely off, check that none of the connections have 12 volts on them. Then put a fuse in the holder and see if you now have 12 volts on one of the trailer socket pins. You could also test it with a continuity test but that takes more effort.

 

[StevieB]

You could also test it with a continuity test but that takes more effort.

And a long piece of wire I bet! I'll have a look for an unused terminal of some kind then. Presumably the lights would have needed something to plug into.
Cheers,
Steve

 

[Old.Tony]

Electric brake controller would use a fused separate connection as well. It has to deliver up to 3.5A (10" drums) times the number of active brakes (so a double axle would need 14A). The wiring ought to be minimum 6 sqmm but bigger is better (I've got two runs of Fig 8 cable - positive and negative - heading to the rear for power, all 21 sq mm, voltage drop over the length is < 0.3V).

 

[[email protected]]

i have that fuse in my navara i ordered driving lights when new, have never checked to see if thats what it belongs to, i have since removed them

 

[landmannnn]

130mA will run your battery flat fairly quickly. The normal draw is 31 to 33 mA.

As well as the above, do you have any phone chargers or an aftermarket head unit?

 

[OldManBeard]

130mA will run your battery flat fairly quickly. The normal draw is 31 to 33 mA.

You're certainly right about that kind of current draw flattening the battery, which is why I plug in the battery charger if I'm not going to drive it for a while. My Nav, which is also a 2012 MY, with no add-ons in-circuit, also draws around the 130mA mark. May I ask where you sourced the 31 to 22 mA info? I'm even wondering if there's a difference between UK and Aus models that can account for the different draws.

 

[StevieB]

i have that fuse in my navara i ordered driving lights when new, have never checked to see if thats what it belongs to, i have since removed them

I followed the wiring to a bundle wrapped in gaffer tape. Inside that was a towbar relay. Replaced the fuse holder and have checked that I have power on the perm live pin so that's all good now.

I'm using the truck more now that we're out of lockdown, so if 130mA isn't completely abnornal then I guess I'll just keep an eye on the battery health. I unplug all chargers when I leave the car and there's nothing else plugged in apart from a USB with music. No mods at all to head unit or anything else for that matter. My snugtop interior light is out so I'll maybe fix/replace that in case it's shorted and is drawing something.

 

[OldManBeard]

... in case it's shorted and is drawing something.

If it's shorted it's either going to blow the fuse or melt the wiring, which generally leads to a fire. A little bit shorted is like a female being a little bit pregnant - there's no such thing.

If you have a current drain then something is using that power and of course the same must apply to my Nav, as I have a similar current draw with the car ignition switched off. To my mind, 130 mA is a little excessive but hardly surprising. With the ignition switched off and no add-ons to consider there are still items using power. The security system, as Tony has already mentioned, and the radio are two obvious examples. I don't know in the case of a 2012 Navara but in general, there are multiple computer systems in most vehicles that still draw a small standby current to maintain their system state. That's why you can often reset systems merely by disconnecting the battery for a while.

One item in my Nav that I had totally overlooked in regards to the current draw is the brake controller. It's one of those things you take for granted and don't think about when you're not towing. The standby current is quite small, about 10 mA in my case, but it's still a part of that 130 mA.

 

[landmannnn]

You're certainly right about that kind of current draw flattening the battery, which is why I plug in the battery charger if I'm not going to drive it for a while. My Nav, which is also a 2012 MY, with no add-ons in-circuit, also draws around the 130mA mark. May I ask where you sourced the 31 to 22 mA info? I'm even wondering if there's a difference between UK and Aus models that can account for the different draws.

With a multi meter. I tested it a few years ago on my 2006 2.5, last week on my V6 model.
I checked my Infiniti with the V9X engine, that was 33mA too.

130mA will draw 20Ah in a week, so flatten the battery in about 3 weeks I suppose.

 

[OldManBeard]

130mA will draw 20Ah in a week, so flatten the battery in about 3 weeks I suppose.

That's near enough to the mark. I had a period last year where I didn't drive mine for something like a couple of months, which for anything else I've ever owned would have been no problem, but had inadvertently knocked the switch that bridges the main and deep cycle batteries together. It flattened all three batteries enough that I couldn't crank the engine. I had to leave it on the charger overnight before I could get the engine started. I must admit that the cranking battery was deteriorating at that point anyway and was replaced soon afterwards, but the deep cycle ones were brand new.

 

[[email protected]]

i have ordered a 12v 200amp continouse solonoid to connect between neg and earth cable it will be exited by an ignition wire . ignition off earth disconnected.
a heavier type to use would be 500 amp winch solonoid

 

[OldManBeard]

i have ordered a 12v 200amp continouse solonoid to connect between neg and earth cable it will be exited by an ignition wire . ignition off earth disconnected.
a heavier type to use would be 500 amp winch solonoid

Sorry, I'm a bit lost regarding context here. What will the relay be controlling? BTW, be aware that winch relays are not designed for constant use, so use them with caution.