Fitting 997 heated seats into 996... Swap for your 996 seats

Hi all, Following on from recommendations by many on here, I bought a set of 997 seats to replace my hardback sports seats. Fitting them physically was very simple, however the wiring connectors are different. After much discussion and trial and error (special thanks to pj_sibley for his personal tuition!!) I gave up and decided I'll get some 996 connectors and rewire the 997 seats. In order to do this properly though, I was hoping someone may have the wiring diagrams for both 997 and 996 heated seats? Would appreciate any help! Cheers :thumb:

Sorry, can't help on the heated seat wiring diagrams. I'm sure there's something out there though, perhaps via a forum like Renntech or 6Speedonline, or even in one of the service manuals? Did you manage to get the recline function working OK in the end with the pins I sent you? Sounds like a sensible plan to buy the 996 seat connector, did you get this from your OPC? Might look at revisiting mine if they're not too expensive.

Managed to get a seat belt buckle together with the whole seat connector on eBay (which was handy as I used the buckle from my old seats to put it on the new ones! It just arrived today, so will have a go once I find the wiring diagram. I called OPC and they only supply the whole loom...

Hi Mazza. I am just doing the exact same with my car. I have fitted the seats and connected the power and seat belt connections. My car hasn't got heated seated but my new seats are heated. I will be over the next few weeks be putting some relays together to allow me to use the stock retractive switches. Fortunately I'm a electrician so these thing come easy to me. If you are in the bucks area I'll happily help out. If your car already has the wiring loom in place for heated seats it will be a 10min job!

911tom, that's a great gesture, many thanks, can you pm me your address and I'll see if I can come up some point and take u up on your offer... Another example of why this forum is so great!

Wiring diagrams for the 1999 Carrera are available for download online. I also have the wiring diagrams for the later turbo if needed. If you need any relay bases for the relay frame in the driver's footwell let me know. I have some spares from when I fitted my tracker. MC

Thanks MC, have arranged to see 911tom who will help me next week, with his expertise should get the electrics sorted!

Right, so spent a couple of hours with 911tom yesterday (many thanks again Tom!) but it seems that fitting 997 heated seats into a 996 is not so straightforward... has anyone done this and got the heated element working? Seems that (in my simple understanding) that the relay for the switch for the 996 heated element is within the seat, whereas for the 997 the relay seems to somewhere within the dash. The conclusion we came to is that in order to get the heated seats working we need the original 996 relay... even then, it seems that the switch will only be on/off and not a 2 step setting (whereas the 997 seats have a 3 step setting). Going to go ask the OPC if the relays can be bought separately, but if anyone has fitted these successfully would appreciate some help! Cheers :thumb:

Right, so after speaking to OPC, and with the help of 911tom (who deserves a medal for his electrical skills and patience!) we finally managed to get the 997 heated seats working in my 996! As mentioned in previous post, the key part was to get the 996 wiring loom for the heated seats. I enquired at OPC and the cost for this loom was over £150+vat... for each seat!! The relay alone is £103+vat!! So, I decided that it might be easier & cheaper to source a pair of cheap/battered 996 heated seats and remove the heated seat wiring loom. Managed to find a pair last week and removed the looms. The next part was to figure out how to connect it all. The loom goes from the connector to the car's main wiring loom. This connector has the power +/- and then 4 other wires which we assumed carry the signal to/from the on/off switch. These wires all go into the relay and then 2 wires come out and in series are connected to the heater elements on the backrest and seat base respectively. There are only 2 wires +/- coming from the 997 heater elements, so these were connected to the 2 wires that go into the relay and hey presto, it worked! The only downside we anticipated was that we would lose the 2 stage setting for the seat, however it seems that this has been retained with the red light indicating hot and amber light warm, so this must be controlled by the relay. So a really big thanks to 911tom and pj_sibley for all their help, and I hope that this post in turn makes it easier for someone else contemplating doing this!

Tentative one this, but after all the work done on getting these seats working, I am contemplating selling these separately as MAY be selling my car and want to restore back to standard... So in the spirit of the forum thought I'd offer an angle to do a swap for my 997 heated seats, for which i'd accept standard 996 (or poasibly even sports) heated black leather seats plus some cash my way (which would be dependent on condition). (Mods, please advise if it's ok to put such a post here, otherwise I can run a separate post in for sale section!)

Interested! I have some 996 sports seats with crests and heating, would need help getting it all working. Car in the garage again so no rush... PM me if you're still thinking. Cheers, Tim

PM sent!

Ok so just to clarify, these are the 997 Standard heated seats (not sport hardback) in black leather. These are all done in terms of correct relays, 996 driver's seat belt, seat and connectors and seat runner trims, so it's a 10 min job to unbolt unplug and refit (rather than the days spent trying different ways, sourcing relays and putting it all together!) Ideally I'd like to do the swap by this Friday, otherwise I will just sell them as standalone seats, so it's a great opportunity if you do want to upgrade with minimal hassle! I'm in west London but happy to travel an hour or so reasonable distance to you to help you with the swap...

Hmmm 10 minute job sounds familiar... Actually Marek I think you and I could do the swap in 5 now! Really is that simple now we have fitted the 996 looms to the seats themselves.

Haha! Couldn't have done it without you Tom! Let's hope someone else can benefit from our persiverance!