Unidentified switch on recently purchased 2015 D40

Dave80 · Aug 26, 2024

Hi all,

I've just purchased a 2015 D40 Navara and there is a switch down between the headlight adjuster and wing mirror adjuster which I've no idea what it is and was wondering if anyone had any ideas. Looking under the dash it appears to be connected into an existing loom connector. Its a brown tearshaped device mounted on the surface with wires coming into it through the dash (I think its 3 wires but hard to be 100%). There is a round button on it which turns a red LED on immediately below the button but I can't see any evidence of it doing anything else. Hopefully the below link will take you to a photo of it.

Many thanks
https://www.facebook.com/share/p/tTYhKghBmA4JQq25/

Dave80 · Aug 31, 2024

Having done a bit more digging under the dash this mystery button it is definitely a 3 wire button and appears to be connected to a connector with TSL 11 stamped on it and then goes into the main wiring loom. I've been unable to find a reference to this on any manual I've found online so far and pressing the button doesn't appear to bring anything up on the dash or make any obvious changes to lights, etc. as far as I can see.

Any ideas much appreciated.

crocodillis · Sep 1, 2024

Looks just like the harness and switches that come with the cheaper work lights
https://www.ebay.com.au/itm/232071804331
https://www.elinz.com.au/buy/wiring-loom-harness-for-led-hid-fog-spot-work-driv/LEDHARNESS

Dave80 · Sep 7, 2024

Yeah various people have thought that it might be for work lights but so far I've not been able to find any evidence of additional lights being fitted and have been unable to track the wiring into the engine bay so far. The other thing that puts me off the idea of it being for lights is that the LED on the switch is very bright to the point of being dazzling when driving at night. I'll do more poking around under the bonnet and try to see if I can find any evidence of retrofitted wiring that gives me any further clues

Gavand · Sep 10, 2024

Cant wait to find out what it is, keep us posted

Dave80 · Sep 10, 2024

I've now had a chance to rummage under the bonnet and identified a lose relay which is driven by that switch (can feel it clicking in and out when pressing the button) but the wiring from it vanishes down into the back of the engine bay and I've been unable to trace it any further. Next step is to try and get it jacked up and go underneath while someone wiggles the wire from above to see if I can track it. I only found the relay because of wiring off the battery that looked slightly different to the rest and followed it and the wiring going down the back of the engine bay is well tucked away so not sure how much further I'll get. Hoping I can see wires popping out the bottom of the engine bay to follow as not confident I'll manage to trace them through the bulkhead.

Dave80 · Sep 14, 2024

Problem solved, it appears to be for the rear demister on the hard top. Unfortunately I've found a burnt out connector in the wiring loom but been able to confirm continuity from it to the demister grid and confirm 12V on the wiring coming in. Replacement connector on order and I'll get it fixed and tested but at least it's another mystery solved!