hi
ive recently putchased new seats, i have the loom for the heated seats but no switch on my dash to operate, can someone advise???
thanks

What do you mean by you have the loom for heated seats? Are you saying that wiring is present in existing loom in car? (Which I would be suprised of in an S) Or have you bought a new loom? 2014 SE Loire Blue SD4 Auto (MY15)
Gone - 2011 GS Baltic Blue, Retrofit Electric Leather, Side Steps, 19"SC's, Roof Rails, TT Sat Nav Mod, Retrofit Premium Audio, Retro fit 2013 Xenons with DRL & Sig Strip (Clutch at 47k)
Gone - 2007 GS Narvik Black, Privacy Glass, 19" SC's, Side Steps,Roof Rails, Roof Spoiler, Lamp Guards, Retrofit Electric Leather (Clutch at 115k)
Gone - 2007 SE Santorini Black (Clutch at 120k)
BT IID (best money ever spent on a car)

There is wiring with a plug not connected to anything present in my car under both front seats which I'm assuming I plug into the new seats. It's the S TD4 (160) model. 58 plate.

Plug should be already connected to your existing seats otherwise your seat safety systems are dead. You will probably have basic loom which doesn't include any wiring for electric seat motors or heating. Best place to start is to take a look at plug under driver seat and let me know what colour wires you have. 2014 SE Loire Blue SD4 Auto (MY15)
Gone - 2011 GS Baltic Blue, Retrofit Electric Leather, Side Steps, 19"SC's, Roof Rails, TT Sat Nav Mod, Retrofit Premium Audio, Retro fit 2013 Xenons with DRL & Sig Strip (Clutch at 47k)
Gone - 2007 GS Narvik Black, Privacy Glass, 19" SC's, Side Steps,Roof Rails, Roof Spoiler, Lamp Guards, Retrofit Electric Leather (Clutch at 115k)
Gone - 2007 SE Santorini Black (Clutch at 120k)
BT IID (best money ever spent on a car)

You can have it done after market where they fit the seat heater switches into the outside edge of the drivers seat just above where the electric seat adjustment switches are, to have them in the dash as standard requires a whole new dash module apparently.

Dash panel is irrelevant if loom does not contain Canbus wiring. 2014 SE Loire Blue SD4 Auto (MY15)
Gone - 2011 GS Baltic Blue, Retrofit Electric Leather, Side Steps, 19"SC's, Roof Rails, TT Sat Nav Mod, Retrofit Premium Audio, Retro fit 2013 Xenons with DRL & Sig Strip (Clutch at 47k)
Gone - 2007 GS Narvik Black, Privacy Glass, 19" SC's, Side Steps,Roof Rails, Roof Spoiler, Lamp Guards, Retrofit Electric Leather (Clutch at 115k)
Gone - 2007 SE Santorini Black (Clutch at 120k)
BT IID (best money ever spent on a car)

Don't know if these pics help in regards to the canbus wiring?

Looking at pics in your gallery it looks like you have basic loom as thought. To enable electric seats you will need to run in some additional wires a permanent live, a switched live and a ground to each seat. You will also need a twisted pair for driver seat to break into canbus. Heating will require additional work and it's not just a matter of changing heater panel for one with heated seat switches. If you are competent enough to read and understand a wiring diagram then getting seats to move is easy enough. 2014 SE Loire Blue SD4 Auto (MY15)
Gone - 2011 GS Baltic Blue, Retrofit Electric Leather, Side Steps, 19"SC's, Roof Rails, TT Sat Nav Mod, Retrofit Premium Audio, Retro fit 2013 Xenons with DRL & Sig Strip (Clutch at 47k)
Gone - 2007 GS Narvik Black, Privacy Glass, 19" SC's, Side Steps,Roof Rails, Roof Spoiler, Lamp Guards, Retrofit Electric Leather (Clutch at 115k)
Gone - 2007 SE Santorini Black (Clutch at 120k)
BT IID (best money ever spent on a car)

Thanks for the advice. Where would I find instructions to do this?

The seats are individually powered via a relay in the seat that requires a switched 12v supply and a permanent 12v supply. I picked up a permanent live from rear fuse box (piggyback fuse) and ran a 2mm cable to each seat (quite easy to run under carpet when seats are out. Pick up 12v switched supply from passenger footwell fuse box (piggy back fuse) on 1mm cable then you need 2 x (-) ground cables run to each seat. Ground point can be picked up under centre console. MS Canbus connection can be picked up under carpet at front right corner of driver seat, you need to make a twisted pair, strip back insulation on loom and spread wire, then thread your new wires through and wrap round existing wires and wrap some insulation tape over joint. 2014 SE Loire Blue SD4 Auto (MY15)
Gone - 2011 GS Baltic Blue, Retrofit Electric Leather, Side Steps, 19"SC's, Roof Rails, TT Sat Nav Mod, Retrofit Premium Audio, Retro fit 2013 Xenons with DRL & Sig Strip (Clutch at 47k)
Gone - 2007 GS Narvik Black, Privacy Glass, 19" SC's, Side Steps,Roof Rails, Roof Spoiler, Lamp Guards, Retrofit Electric Leather (Clutch at 115k)
Gone - 2007 SE Santorini Black (Clutch at 120k)
BT IID (best money ever spent on a car)