Wiring Heated Seats to a R1250GS that was supplied without.

Nick Marshall · 2026-09-12T12:30:44+0100

I am looking to wire a pair of factory heated seats to my 2023 R1250GS.

I have been told by BMW Motorrad that you can’t fit the loom. See first picture. Although I can’t understand why not!

So. I plan to wire the riders seat to my HEX ezCAN and use on the heated clothing setting via the heated grips.
That will give me 5 different settings.

With the BMW Heated pillion seat. I plan to also connect to a seperate output on the HEX ezCAN. That should give me two different heated seat settings via the on board pillion seat switch.

Can anyone with a R1250GS or Adventure confirm if this is the 4 pin correct plug Thant would fit into the pillion seat?
I could buy the looms item 2 and 3 in the diagram.

https://www.ebay.co.uk/itm/286120125816?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20250417133020%26meid%3D899f8275fda441fcbc45b37616abfe2f%26pid%3D102726%26rk%3D1%26rkt%3D1%26itm%3D286120125816%26pmt%3D0%26noa%3D1%26pg%3D4375194%26algv%3DRecentlyViewedItemsV2DWebWithPSItemDRV2_BP%26brand%3DBMW&_trksid=p4375194.c102726.m162918

Any help or info would be appreciated and may help others considering this modification.

Thank you.

richh · 2026-09-12T12:42:56+0100

I thought they were plug and almost play on the later models.

Know it’s not as easy on my 2020.

Sent from my iPhone using Tapatalk

Victor c · 2026-09-12T18:45:21+0100

The connector in the eBay link is not the correct one Nick. The oem connector for the rear seat has stacked pins, in two rows rather than 4 inline. I have pictures, but can’t post as I’m no longer a subscriber. However, if you want to WhatsApp me, my no is zero779199024nine.

On a side note, I have two working gsa heated seats that have slight damage to their covers going cheap.

Mark

Victor c · 2026-09-12T18:48:10+0100

This is the one you want. It’s the same part number as on mine https://ebay.io/m/8uTayj

Nick Marshall · 2026-09-12T19:28:15+0100

Victor c said:
The connector in the eBay link is not the correct one Nick. The oem connector for the rear seat has stacked pins, in two rows rather than 4 inline. I have pictures, but can’t post as I’m no longer a subscriber. However, if you want to WhatsApp me, my no is zero779199024nine.

On a side note, I have two working gsa heated seats that have slight damage to their covers going cheap.

Mark

Really appreciated. Thanks Mark.
Thanks for the offer of seats. However, have a couple of hopefully very tidy seats on the way.

Thanks also for the link to the used plug on eBay. I will probably go for a new BMW loom as there around £20. Then I can solder a plug on it to the ezCAN when I meter out the two wires I would need so the pillion seat switch works.

Nick Marshall · 2026-09-13T08:51:50+0100

Found this on line.

Factory Wiring Reality

- Missing Loom: Unlike some other BMW models, a 2023 R1250GS built without factory heated seats typically lacks the sub-harness, switchgear integration, and software activation needed for OEM seats.
- TFT & Switchgear Integration: Factory heated seats are controlled via the TFT display and the right-hand switchgear (sharing control menus with the heated grips). If your bike only has a heated grip button, the computer and loom for the seat are usually absent.
- Check Your Bike: You can lift the rider seat and look near the battery/relay area to see if an unused OEM 4-pin or 2-pin connector is tucked away, though community reports on UKGSer and ADVRider note that most non-heated spec bikes come completely un-wired.

Nick Marshall · 2026-09-13T08:54:07+0100

Also this. Which appears to be a plug from the loom 61121683927

G&T · 2026-09-13T08:59:45+0100

So does this mean you can or can’t do it with a BMW sub harness loom? As you know I have a 2023 1250 Rallye.

djgsa · 2026-09-13T09:11:58+0100

I'd be really keen to see how you get on with this

Nick Marshall · 2026-09-13T09:15:19+0100

G&T said:
So does this mean you can or can’t do it with a BMW sub harness loom? As you know I have a 2023 1250 Rallye.

I honestly don’t know yet.
Plan to go have a chat with Gary & Lewis at Shrewsbury Motorrad.

At this moment in time I have no idea where that big white plug I pictured above plugs into. Or if I have to buy anything else.

Nick Marshall · 2026-09-13T09:22:24+0100

djgsa said:
I'd be really keen to see how you get on with this

Me too.
If it can’t be done. I know I can wire both seats via a HEX ezCAN. As I had my recently sold Wunderlich riders seat connected that way.

Settings were.

Heated Grips. Heated Rider Seat.
Setting 1 - 20% 10%
Setting 2 - 40% 20%
Setting 3 - 60% 30%
Setting 4 - 80% 40%
Setting 5 - 100% 50%

Hann · 2026-09-13T10:36:40+0100

I don`t think you`ll be able to use the switch on the side of the pillion seat to control your heat settings (unless you get really inventive with it and completely re-work the wiring to incorporate that switch......)
The riders seat is a two-wire jobbie which is directly to the heating element so your Ezcan will hook up to that easily enough.

The pillion switch does not form any part of the actual power circuit for the heating element it just has two control/signal wires to inform the ZFE that you have selected heat.
The ZFE then supplies power for the actual heating element on another separate circuit.
If you look really carefully at the socket on the underside of the pillion seat (i had to use a loupe!) you`ll see the pins are numbered;
Pins 1 and 2 are the heating element (you can check this by measuring resistance across them, should be about 9 Ohms), pins 3 and 4 are the control/signal to the ZFE.
You could hook your Ezcan up to a plug with pins 1 and 2 used for the heating element but pins 3 and 4 would be redundant.

4 2
3 1

Santa-2512 · 2026-09-13T10:49:47+0100

Two problems

How are you going to control the heat output?

And how are you going to power it

If your running of the bikes own loom,

And the seat(s) draw more than 5 amps

The can bus will see the abnormal load and kill the circuit it's on ( along with anything else on the circuit)

ALso how are you going to control it! If it's not got a dedicated switch, or coded in the TFT

You need to figure that out

If your running from a hexexcan, you only get a simple on off toggle , and you also need to look at current draw, as again there is a limit to what can be drawn before the circuit shuts down

And if it does. You need a lappy to change settings, handy if your in the middle of Scotland, and it's snowing

Nick Marshall · 2026-09-13T11:30:36+0100

Thanks Hann for the above.
Think I might have to get inventive then.

If I can’t wire my seats in the conventional way.
I would like to put a supply from my ezCAN to the pilion seat switch and at least have the opportunity
to have an OFF and an ON selection.

Or possibly piggyback it from the riders seat heating. But with the possibility of switching OFF via the pillion seat switch.

Not really bothered about using the pillion heat as my wife will no longer ride pillion and also does not appreciate a warm bum. But I would still like the pillion heat to work.

Victor c · 2026-09-13T14:11:12+0100

Nick Marshall said:
Also this. Which appears to be a plug from the loom 61121683927

View attachment 538446

Not sure mine has a large plug and socket like that. From what I can see, the front seat wiring goes under the silver plastic subframe trim and is plugged in to a two wire socket, on the left side of the bike, just below the riders seat left rear catch. It’s difficult to see where the pillion wire goes too, but I suspect it is too a connection in the same area.

Edit, just looking at the online parts for the loom and maybe the front and rear seats do plug into the adaptor with the rectangle connector, which in turn, connects into the bikes main loom somewhere.

Nick Marshall · 2026-09-13T15:11:56+0100

Victor c has sent me the following pictures from his R1250GS Adventure fitted with heated seats.

The more info I can get on the subject in one place the better.