Hi folks,

This is a bit "what if" at this stage, just trying to understand what's possible - once I get the car mobile again! However, like the title says, my car has very basic grey velour seats, with only the up/down button on the drivers side, and even that's broken off and missing.

If I spend some more time and money getting the running gear sorted, and it looks more like the car is a 'keeper' then what are my options for replacement seats?

I see there's a couple of breakers doing complete interiors. I don't want to change the colour at all, but if I found a good set of grey leather seats are they a straight swap over? They seem much more commonly available with all of the adjustment buttons. Would they go into my car at all, and/or would the BECM need to be amended/reactivated?

If the answer is a straight no, then that's fine - one less thing to think about!

Any advice gratefully received as always.

Ta

Donald

You options go as far as your capability for tinkering and budget available go.
The seats always mount in the same locations with the same bolts -BUT if you have manual and want to fit electric, you do need to check you have the harnesses in the vehicle (under the seats). And yes, they run trhu the BeCM so someone might need to check into it.
This said, if you are willing to let the electric adjustment go, you can mount other seats' parts (this is leather, foam cushions) to your manual seats' bases, so you can upgrade without messing around with the existing setup.

Thanks Leolito,

They aren't 'manual' as such... at least I don't think so. The manual ones have the small lever for up and down, don't they?

I have a manual control for back and forward adjustment, but there's a switch and motor for height adjustment, or as I say, there's supposed to be. I also have a nanocom, so could use that to turn on the BeCM functionality couldn't I? Is it as simple as just turning it on, or would a 'manual seat' BeCM not leave the factory with the required programming?

As far as the loom is concerned I imagine that they wouldn't fit the whole electric loom if the seat was only capable of going up and down, but I have to say I haven't checked.

Again, I "imagine" (doing a lot of that amn't I!) that a full seat loom would just be 'plug and play' if sourced from a breaker? But maybe that would be too simple...

It'n not so much of a BECM setting, as whether your logic board will support memory seats. Low line logic boards don't physically have the components on them to allow the seat outstation to communicate with the BECM. You would need a High Line logic board to do this, and have it reprogrammed to your vehicle.

If you just wanted electric but not memory seats, then you could pretty easily wire the drivers seat up (as the passenger one on a RHD vehicle is by default) with a couple of relays to be able to power the motors directly via the switches.

It's a bit more work (or maybe even a LH seat loom would work on the RH seat) but definitely possible to get most of the functionality without having to mess with the BECM.

If you have a High Line BECM, then you can just plug memory seats straight in and they'll work - there's nothing extra to do in the BECM settings wise.

Thanks Marty,

I hadn't thought of (and am not bothered about) the memory side of things. Just going up and down, and back to front would do me fine, as the reason I am even considering this at all is simply to replace old velour with more long-lasting leather, not specifically to get all of the seat functionality. In my wife's car, which I occasionally use, then the only adjustment I ever make is pushing it back a couple of inches.

Strangely enough I haven't sat in the RR passenger seat since the first 5 mins of my test drive. It's wired by default, even if not use? That is interesting.

How would I know if I have a High Line BeCM? Would that just be because of the various options in the car, or could you have a high line version on a low-spec car?

donmacn I just did the manual to electric swap a few weeks ago. If You get the seats with memory You should disable the door mirror adjustment when engaging reverse ... otherwise You end u with maladjusted mirrors every time You reverse. Ingintion on, engage reverse and press memory button on the seats for longer than two seconds. Message centre will tell You "mirror dip off".
It is absolutely worth the work, the electric ones are much more adjustable and have a lumbar support. You can swap the seat bases, so getting a less used passenger side base makes the seat feeling even more like new.

Hi Line BECM is a written "H" on the label visible on top of the BECM if You open the fuse box in the right seat base. Might be covered in many layers of dust ... so wipe gently ;-)

We really should be swapping front drivers and passenger seats across the Atlantic so we all end up with more life in our drivers seats.

If it is of any help, I've got fully manual seats in mine, not even the electric up and down movement just the lever, and I also have a high line BeCM. I've never seen a dangling plug under the seats to power electric ones but equally I don't recall ever having seen a blank socket on the BeCM where a loom would be plugged in either. I do have a warning on the dash every time I turn the ignition on that says Fuse 20 Blown which is odd as Fuse 20 isn't blown and feeds the passenger electric seat I don't have. One day I'll get around to pulling the power board out of the BeCM and replacing the resistor that causes false blown fuse messages and I'll probably think something is wrong as I won't get a beep from the dash every time I switch it on.....

Thank you gentlemen, I'll investigate further - once I've got the car back on the road! I'll excavate the BECM and see what it looks like. No need to worry about the mirrors - don't think either of them work!

Gilbertd You might have heated cloth seats? They were available ... so there might be a shortage in the circuit? With heated seats only the wiring loom under the seats is just for the heater (two plugs if I remember correctly, base and backrest).
The wiring for the electric movable seats is a separate additional loom, the plugs in the BECM are on the side of the transmission tunnel, so You have to remove the seat to get to them. Easy plug and play. C912 in the ETM.
I removed the loom from the donor car together with the seats and removed the heated wiring loom, as this is integrated in the electric movable loom already.
IIrc heated seats mean highline BECM (like sunroof and some other options).
I had manual heated leather seats in genuine trim to make confusion complete.

Yes, heated cloth seats, so the only dangling plug(s) are the two for the seat heaters. MXC2112LNF is the part number for Front, Manual, Heated, Ash Grey Cloth but that is listed as only up to VIN WA376579 yet my VIN is WA 381091 but as it was a special order spec for the police, it could have any options that weren't available on production models. Despite the poverty spec interior, I've got the front fogs and headlamp wash/wipe which a base model wouldn't have, along with the 7" x 16" wheels which were only fitted to a base spec rather than the 8" x 16" or 8" x 18" that all the others came with.

Looking at the BeCM connections for C912, the supply for the seat heaters as well as the power for the electric seats all come off that one socket. I suspect I've got a loom that only contains the seat heater wiring and not the full set.

Evening all,

As I now have a new MOT I'm indulging in a little more seat speculation!

Having read up some more, and digested what's in the replies above I think I'm more informed.

The label on my BECM has gone completely blank - only the LR logo remains - but as I have a sunroof; a mid-range speaker install; and an electric height adjustable driver's seat, I believe I have a Highline version.

I now know that the loom for the driver's seat (height motor only) has a green plug, and plugs into the BECM on the side next to the transmission tunnel. I have no idea if there is any 'default' wiring for the passenger seat under the carpets.

So I have three (!) questions at this stage:
1) I've read about seat 'outstations' or ECUs, and seen one on ebay. But it was a 1995 part. My car is 2000, maybe even a 2001 build judging by the VIN number. Do I need to get seat ECUs/outstations?

2)Just confirming what Marty said above - if I have a Highline BECM, the driver's seat is just a simple plug and play?

3) passenger's seat - if there's no pre-installed wiring, and I get the loom with the replacement seat - how does that work? Marty's reply suggests it's not a BECM thing, but a relay-based installation. Will there be a plug to connect to somewhere, or does the wiring for this run under the carpet to the BECM?

As always all advice really appreciated.

Ta

1) Seat outstations are only needed if you have the memory seats not just electric seats. As far as I know, there's no difference in teh actual seats themselves, just whether or not they have the outstation (yet another ECU) to control them.
2) On a Highline BeCM you'll have the supplies for the seats, just not the loom from BeCM to seats, so adding the looms should make it plug and play.
3) Yes, wiring will run to the BeCM. The diagram shows power relays between BeCM and seat so I assume they will be in the loom as they live under the seats.

Outputs for the seats are there in a High Line BeCM. For the last 6 years my dash has been telling me that Fuse 20 is blown. Fuse 20 feeds the passenger electric seat. Fuse 20 isn't blown and as I have manual cloth seats it wouldn't matter if it was. I actually prefer the poverty spec, cloth seats that plod specified when they ordered the car new. They aren't freezing cold in mid winter and not hot and sticky when the car has been parked in the sun. The Ascot has leather and it looks better but not as comfortable as the cloth. It's a bit like wheels. 16" for comfort and 18" for looks.

Thanks very much Gd. It does sound as if it shouldn't be too difficult then - famous last words.

I know what you mean about the leather vs cloth thing. Our 'sensible' car - maybe until I trust the P38 as much as you do! - is a Skoda Yeti. Black leather seats, but they are heated and the car has A/C - though we don't get the sun so much away up here!!

So this is definitely 'frivolous' as I'm sure the existing seats are functional enough. I suppose I just feel some nice, soft leather seats are just a RR is all about!

If I go for it, I think the seats would come with looms etc, but I'd make sure to ask.

Thanks again.

Hhmmm, interesting, I’ve been offered a set of black leather seats from a 2020 hi line Audi for £50, was thinking of changing mine as these are smart to say the least

that sounds .... very low. if they are mint, worth snap them right away!

I notice that the discussion point that ran for quite a while on the Mercedes owners forum [classics] has popped up here as well. Are velour seats better/nicer than leather.

My '83 Mercedes W126 has velour, and I specifically held off buying a W126 until I found the grey velour interior that I wanted. As Gilbert says it is much more comfortable on either very cold or very hot days - no burny-bum issues.

I do like the leather in the P38, and in a Lexus IS300 that I have, it is soft and wears well, but velour is like sitting in the 3-piece settee at home.

Incidentally, velour was around £600 more than leather in the '83 Mercedes W126.

Pierre3.

Funny how things change. 100 years ago, all cars were leather trimmed. Some manufactures offered cord/velvet/mohair trim for an exorbitant cost.

We then move to mid century and cars are trimmed in various grades of "hard wearing" (let's say) plastics of one form or another, with velour/soft trims almost unknown and leather available on some up market vehicles.

We then come towards the end of the century where most manufacturers offer velour style as standard and some offer leather as a very expensive upgrade.

We are now at the point (having been in discussion with a leather producer for work related reasons) that the international leather market is at its lowest point for 50 years in terms of price and inventory is at astronomical levels (it seems people might not buy leather lounges, but they still eat beef) so raw material costs are extremely low, so leather trimming is a viable option again.

That is an interesting analysis indeed. Although it isn't so warm and comfy as cloth or velour, I like leather a lot.
On a car of a certain level, would not consider otherwise ...

So, time moves on slowly…..

Today, in between rain showers, I stripped out the interior of my car - seats and carpets. I got the black/dark carpet in OK, and just the “new” driver’s seat before rain stopped play for the evening.

However, none of the buttons does anything - no movement anywhere. 90% sure we checked all the motors and adjustments before taking them out of the donor car ( but that was probably about a year / half ago, so my memory might be playing tricks).

As above, my original driver’s seat was supposed to have some power adjustment, though it didn’t work; the passenger seat had nothing. So I also installed the seat loom that was removed from the donor car, which runs both seats.

These seats do have memory options - though I’m completely not bothered about that, but not sure if that would affect their operation?

Do I need to go into the BeCM via nano and ‘activate’ electric seats? Is there a fuse in the circuit that might be missing?

I have to say I’m away from my home PC and my manuals, so at this stage I haven’t been able to check the circuits.