DIY – Inverter remote power switch (Kings)

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Please note: The information below should be considered as ‘legacy’ information, relevant to the original ‘blue’ Kings 1500W inverter (with dual outlets), as shown in the image below. This DIY switch hasn’t been tested with the new (2023) Kings MkII 1500W inverter….

Alert iconIn December 2021 the Kings 1500W inverter we purchased (the blue one) was superseded by a new model (the black one), which was not compatible with the current Kings remote power switch.

In June 2023 the ‘blue’ model was re-introduced as the MkII 1500W inverter, with ‘updated internal circuitry’.

The DIY switch wiring configuration detailed below is not compatible with the ‘black’ Kings 1500W inverter, and I have not tested it with the ‘new’ (2023) MkII blue inverter – though I expect that compatibility with the Kings remote switch may be one reason that the ‘blue’ inverter made a MkII return!

I have left this info here for those who may have an original (blue) Kings 1500W inverter and are interested in having a tinker with a DIY remote switch. Hopefully the DIY option will also function with the new MkII blue inverter.

Others in the community have explored options for a DIY remote switch for the ‘black’ inverter. It looks like the ‘black’ inverter requires a rocker type on/off switch and more complicated ancillary circuitry, rather than a simple momentary on/off switch as used on the ‘blue’ inverter. Read more about a remote switch for the ‘black’ inverter on this Whirlpool forum >>> 

We have since replaced our original Kings 1500W inverter with an iTechWorld 2000W inverter.



Kings 1500W inverterMost inverters are large units – our Kings 1500W inverter measured 420 x 240 x 110mm.

It is likely an inverter will be installed in a cupboard, under a seat, or in another out-of-the-way location close to the batteries – which might be difficult to access when you need to use it.

We installed our inverter adjacent to the batteries under the seat / bed in our Campervan. The inverter should be turned off when not in use, to minimise stand-by current draw (~0.5 amp per hour). To avoid lifting the mattress and opening the cupboard each time we wanted to start up the inverter, or connect an appliance, we installed a remote access switch and power outlet. (The installation of a remote power outlet should be carried out by a licensed electrician.)

Some inverters include a remote access switch. For others, it is an optional extra. At the time of our purchase (2021), the Kings inverter included a remote access port – an RJ12 socket, similar to an old-style phone socket – but no remote switch.

Since then Kings have released an optional remote power switch, which is now often included in an inverter bundle option.

However, we found the Kings remote switch to be too bright at night inside our Campervan – the LED lights stay on even when the inverter is turned off. So we stuck with our small DIY switch.

Please note – I haven’t tested this original DIY switch with the ‘new’ Kings MkII blue inverter, though am expecting that the ‘new’ blue inverter will have similar remote switch functionality as the previous blue inverter model.

Keep in mind that at $25 the Kings remote switch is now around the same price as the parts for the DIY switch, so the standard shop option may be an easier and more viable option than heading down the DIY path, depending on your particular setup and installation requirements.


Info iconNote 1: There does not appear to be any industry standard for the wiring of the socket for a remote switch in inverters. Every manufacturer appears to have a different wiring setup, making it nigh impossible to mix and match remote switches with different brand inverters.

The wiring suggested here is for the original ‘blue’ 1500W model of Kings inverter, which was superseded in December 2021 by a ‘black’ model. This particular wiring configuration will not work with the 2022 ‘black’ model of the 1500W inverter, but should work with the re-instated (2023) MkII ‘blue’ model inverter.

We have moved on to a different brand of inverter (April 2022) so haven’t explored the functionality of the DIY switch with the ‘new’ MkII blue inverter model.

If you have an interim ‘black’ model 1500W inverter it appears that a ‘permanent’ on/off switch (eg a rocker switch) is required for these inverters, along with some ancillary circuitry, rather than the momentary on switch described in these notes. Read more on this Whirlpool forum >>> 


Making it Happen

remote switch and cableA remote switch was a ‘must-have’ for us, and with no remote switch available from Kings (at the time) we went down the DIY path, equipped with YouTube and a multi-meter, and inspired by Trent’s explorations in the video below….

Rather than make up a cable with an RJ12 plug as suggested by Trent, we bought a ready-made cable from Jaycar (all 6 pins wired), along with a ‘momentary on’ switch (SPO802 – Blue LED).

  Note 2: We didn’t rush out to buy a Kings remote switch when they eventually became available for the original blue 1500W inverter – the small DIY push-button switch we installed was a ‘neater’ installation than the large (and a bit garish) Kings option. The Kings remote switch also has a bright blue light that is permanently ON, even when the inverter is powered off, which isn’t suitable for use in our Campervan environment – especially at night.  

Remote switch wiring schematic

After cutting one end off the pre-made cable, some careful work is required to strip and solder the very fine cables to the switch. Looking at the RJ12 plug from the ‘back’ (click-connector facing away from you) – cables 4 & 6 are connected to the NO & C terminals on the switch (Normally Open and Common) while cables 3 (+ve) and 5 (-ve) are connected to the respective +ve and -ve terminals on the switch for the LED light. (You will need good eyes to see the + symbol adjacent to the +ve terminal!)

Switch soldered

The voltage across pins 3 & 5 looks to be around 3V, so the LED is not overly bright – I expect that it is designed for 12V – but it works just fine in our setup. Using cables 3 & 5, the LED is only illuminated when the inverter is powered on.

In conjunction with an auxiliary power outlet, this arrangement facilitates much more convenient ‘remote’ access to the inverter functionality, without requiring direct access to the inverter under the seat.

Inverter remote outlet



The 230V AC output from an inverter is just as potentially lethal as the output from a domestic power outlet.

Any cabling or modifications on the 230V side of the inverter must be carried out by a qualified electrician.

safety sign


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