[Jem]

RESOLVED - Smart fob range massively reduced after adding auxiliary devices and associated wiring

Hi guys,

Think this has been covered before, but I can't find it....

Went out to my truck earlier, unlocked it and started it, all keylessly.
Only travelled approx. 2.5 miles, and stopped the truck, but when I came to lock it, it wouldn't, neither keylessly with the button on the handle, or with the button on the fob.
Got back in to try and start it, and the screen said "no key detected". Put the fob right up to the start button and it worked. But still wouldn't work to lock the truck.

Replaced the battery in the fob, with no change. It still won't remotely lock/unlock the vehicle, or start the engine unless pressed right upto the start button.
Tried a second new battery (from the sam, previously opened pack), still the same.

I've had the pack of batteries for quite a while (probably since last time it needed replacing), but it says best before 2025.

Do you think it's a battery fault, or something else?

I have been doing some electrical work on my truck today, but the only way it's had anything to do with the truck's own wiring etc, is I've connected a new fuse box directly to the battery.

 

[pistol6000]

Have you added anything "wireless" to your Nav, Could be interference

 

[Jem]

Nope. In fact I've removed a wireless remote relay which was controlling my light bar. I've added a fuse box, and cabling.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[Jem]

Tried disconnecting new fuse box from the battery, and new switch panel from interior fuse box. Still the same.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[Jem]

After I finished installing the new auxiliary wiring, I was able to lock up. Then I unlocked and started no problem an hour later.

It was only after a short drive that it started playing up.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[popsdosh]

After I finished installing the new auxiliary wiring, I was able to lock up. Then I unlocked and started no problem an hour later.

It was only after a short drive that it started playing up.

Sent from my mobile device. Please excuse brevity and mistakes.

Mine did that one of the times it drained the battery! will be interested to know if your has now . Has never done it since but ready with volt meter if it comes back. Did you get a very faint beeping as well?

I got to end of journey and when I stopped the vehicle I got the cannot recognise key and wouldnt lock however I tried .I knew it wasnt key as new battery had been fitted at dealers a week earlier. It was flat enough not to start within an hour and a half . I put it down to having key in pocket with other stuff as mine has a habit of locking and unlocking if im within range and a key button inadvertently gets touched and wondered if mine had managed to fool itself into some mode .

 

[Jem]

Last night, I disconnected all my new wiring from the truck and left it disconnected over night. This morning, still not working.

I decided, where I'd mounted one of the fuse boxes, was very close to a main wiring loom. Moved this and the door buttons started working.

Reconnected all my wiring bit by bit, tested the doors as I Went, and it all worked.

Started the truck and tested the light bar, to check my wiring, and it worked.

Turned the truck off, locked the doors.... nothing!

So now, the buttons on the handles don't work, but the ones on the fob do, but only if stood right next to the door. The start button works now with the key I'm my pocket.

It's an improvement, so maybe I just need to move the fuse box further away again?

What do you think?

Sent from my mobile device. Please excuse brevity and mistakes.

 

[landmannnn]

I guess firstly, check the main battery is 100% charged, perhaps put it on charge overnight.

 

[Jem]

I guess firstly, check the main battery is 100% charged, perhaps put it on charge overnight.

I've not got a charger. I'm going on a fairly long run tomorrow, so hopefully it'll get a chance to charge.

I've removed all my auxiliary wiring today. It's made an improvement, but there's still very little range on the remote fob.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[RandomKamikaze]

Did you use new grounding points for your own work? Or existing ones?

 

[Jem]

My own grounding points, but proven ones I've used before.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[Jem]

Just noticed in the handbook, that you're not to ground to the negative side of the battery, which I did for one thing (can't remember what). Apparently this bypasses the smart alternator, which then doesn't know how much current to supply.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[Jem]

Truck behaving normally this morning. Might start again when I'm back from my travels next week.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[s60r]

Glad you have got to the bottom of it Jem..... so to be sure.... you cannot have the negative at the battery grounded to body work at all?

I will be adding stuff down the line and don’t want to fall into the same trap.

 

[Jem]

No, the handbook says, don't ground accessories to the battery, so do it to the body work instead.

Not convinced that's what caused my issue, it's just something I read while trying to figure out what was going on.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[popsdosh]

No, the handbook says, don't ground accessories to the battery, so do it to the body work instead.

Not convinced that's what caused my issue, it's just something I read while trying to figure out what was going on.

Sent from my mobile device. Please excuse brevity and mistakes.

Interesting the Nissan trailer wiring harness takes both +ive and -ive from the battery

 

[Jem]

Page 8-23 of the handbook;

"CAUTION:
Do not ground accessories directly to the battery terminal. Doing so will bypass the variable voltage control system and the vehicle battery may not charge completely."

Sent from my mobile device. Please excuse brevity and mistakes.

 

[popsdosh]

Page 8-23 of the handbook;

"CAUTION:
Do not ground accessories directly to the battery terminal. Doing so will bypass the variable voltage control system and the vehicle battery may not charge completely."

Sent from my mobile device. Please excuse brevity and mistakes.

wasnt doubting you ,just wondered how the trailer wiring loom was different as it potentially has a large draw if charging an extra battery. mine has nearly always got an extra battery on charge in the back connected to the trailer wiring. Funnily enough when mine has played up there has not been anything charging.
Have you spoken to Nissan as the more who report this thing will make them look into it.
I am considering putting a battery voltage monitor on the truck like we have in a couple of HGVs just so I know I wont get stuck anywhere with a drained battery.

 

[Jem]

I suspect the dealer (or whoever fitted the trailer wiring) wasn't aware of this. It wouldn't surprise me at all.

Sent from my mobile device. Please excuse brevity and mistakes.

 

[popsdosh]

I suspect the dealer (or whoever fitted the trailer wiring) wasn't aware of this. It wouldn't surprise me at all.

Sent from my mobile device. Please excuse brevity and mistakes.

Nissan need to change their wiring instructions then and the loom as the positive and negative terminals are designed to go on the battery.
When I get the locking problem it creates a large draw on the battery its not due to the charging not working it will flatten itself in 30 mins . However sods law when waiting for it to happen its not for about 3 months now. Im convinced its the key in my pocket sending lock and unlock signals that are sending it into some odd mode.