infected

Here is a quick DIY for installing aftermarket seats into a Coupe.
My Coupe is a 2003 C230 with leather/heated/manual seats.

Disclaimer: Everything here is based on my own experiences. I work day in day out in a shop. If you are unsure about what you are doing then please have a professional do the installation. Use the following information at your own risk.

TOOLS:
- If you don't have a torx set then I would suggest you pick up a set soon if you plan to work on your MB a lot. I like MAC but anything works as long as it comes with regular and inverted sockets, and a couple wrenches.
- Some different size flat heads will also come in handy.
- Side cutters
- Knife/exacto

The first thing you want to determine is whether you want a solid bucket or reclineable. If you go the solid bucket route, be sure it is suitable for a 5 point harness because you will need to run the airbag sensor through the hole for the crotch belt on the passenger side.

Seat brackets are hard to come by for the Coupe. Some manufacturers will reuse parts of the stock rails while others offer a complete replacement. Be sure to specify your application is for a Coupe and also the year when ordering brackets. Sedan brackets will NOT fit so do not waste your time as I have already tried them in the past.

Do NOT place the key into the ignition at anytime there are open connections. Make sure everything is plugged in and secure to avoid paying the Dealer a visit.

For my application I decided to go with the Recaro Speed seats with one-off Bride brackets.



DRIVER SEAT:
Begin by sliding the seat all the way back and remove the two torx bolts. Slide the seat forward and remove the remaining two torx bolts. Gently allow the seat to fall back and rest on the rear bench seat. You will now be able to see a connection box under the seat as well as the main harness coming from the car. The main harness wiring should be attached to the seat with zip-ties. Cut the zip-ties holding the main harness to the seat. Disconnect all the connections from the main harness to the connection box under the seat. The seat is now ready to be removed.



Lay the seat back to reveal the connection box mentioned earlier. There is a cover clipped on the bottom of the box that needs to be removed. You will now see the plugs are held in with a plastic tab. Use a flathead and push back the tab to release the YELLOW plug. The plug has 2 wires and is for the seatbelt. Follow the wire and remove it from the seat. There is one torx bolt holding the seatbelt receptacle that needs to be removed as well.



Attach the seatbelt receptacle to the aftermarket bracket and tuck the wire nicely. You do not want the wire to get caught on the sliders after the seats are installed. The aftermarket seat is ready to go in. Place the seat in the car and allow it to lean back on the rear bench. Connect the seatbelt sensor and tuck all the wiring neatly and away from any moving parts. Allow a little slack so you will still be able to slide the seat forward and back without stretching the wiring.

Bolt in the 4 torx bolts and we're finished the driver side!



PASSENGER SEAT:
The passenger side almost exactly the same as the driver side. The only difference is the seat occupancy sensor in the passenger seat. In the case of an accident with a child or baby in the passenger seat, the airbags will not deploy. Without the sensor, there will be a SRS light on the dash only the Dealer will be able to reset. Different manufacturers have different airbag systems and I am uncertain if only the passenger side airbags will be turned off with the airbag sensor disconnected or all the airbags will be turned off. The system can be bypassed with a resistor that will trick the computer into thinking there is a passenger at all times. In the case of an accident the passenger side airbags will deploy regardless of whether there is a passenger or not. I do not recommend this option but if you are looking for a cheap alternative then feel free to play around with the bypass. I will not be giving any information on how to bypass the system so please do not ask. For my application I decided to retro-fit the airbag seat sensor into the passenger side Recaro. You may rip out the sensor in your current seat or pick up a new sensor. I picked up a new sensor to avoid cutting into the stock seat so I may return the vehicle to stock in the future if I wished.

The airbag sensor is 203 821 62 51.

Be careful when handling the sensor, it is thin. For my application I managed to remove the cushion and placed the sensor below. Make sure the black points are facing UP. Do not confuse the seatbelt sensor and the airbag sensor as both the plugs are yellow. The seatbelt sensor has 2 wires where as the airbag sensor has 3 wires.



Take a knife and cut a small opening in the bottom of the seat to allow the wire for the airbag sensor to run through.



Everything else is exactly the same as the driver side.





The finished product!



The Recaro seats are roughly half the weight of the stock seats. I wouldn’t be surprised if I saved 100 pounds just by replacing the seats. There are no seatbelt error lights on the dash due to the transfer of the seatbelt which also covered the issue of the seatbelt tensioner working correctly. Airbags are also fully functional.

I hope you found this write-up helpful.

ChristianJan

Wow, looks good bro. Wish I had the cash to do this. Great write up!

nrg_mike

Looks great man! It's also much easier to adjust new seat vs the old one. Stupid factory turn knob! lol

laneshift

Very nice DIY and coupe. Looks sharp.

Performance upgrades?

AdidasC230

looks good, but why are the seats leaned so far back in the last pic?

NegroC230

nice..thanks...im literally days away from ordering CF seats ( fixed ) and putting them into my skinny lady C230 , she has lost soo much weight since i got her, and this will be one of the biggest diet plans i did. Aiming at about 120lbs loss Will post photos aswell, when i get them in finally.

infected

Yes, lots.

I like to drive like that.

tommy

Looks great. I'd say it needs some color, but that's personal opinion.

For those contemplating this mod, the Recaro brackets use the stock sliders and attach to them. I'm not saying which is better, because I only have experience with this on my seat, but it's another alternative.

Infected - did this drop the seat? My seat's a bit lower than what was the lowest setting on my manually-adjusted seat. Just curious.

mk4mike

get them wrapped in leather/alcantara!

infected

The rails are custom made and I like to sit low so yes the seats are much lower than stock. Driver side rail is touching the floor and the passenger side rail is 1" higher.

Midnight Koop

great writeup!

its about time someone on this forum posted a DIY on this...

i have two questions:

(1) what are "one-off Bride brackets" ? and where can buy some? the recaro brakets are way too $$.

(2) is it possible to provide another picture on how/where you removed the cushion and placed the sensor below? were any cuts necessary other than the one running the wire below?

thanks in advance

TemjinX2

great write up even though i like the stock seats.

CoupeCrazy03

Looks good Terence This will definitely help me out if I decide to get a bottom mounted Recaro for my passenger.

03MBC320

looks real good, great DIY

Jerkin

hey infected where did you get the brackets? Because no matter where I search I cannot find bottom mounted brackets for my car.

tommy

Why not just buy the adaptors from Recaro?

Don Nguyen

Pretty cool. You don't see people doing this too often on Benzes. I helped one of my friends get some STATUS racing seats for his E55, back when they actually gave me a sponsorship for one of my cars.

-Don

Jerkin

What do you mean by adaptars? And where can I get them?

tommy

It's like an erector set; remove the top part of the OEM slider, attach the Recaro one, and presto, you're good to go on istalling the Recaro bottom-mount seat. It's pretty easy, and can be done even while watching bad sitcoms and drinking beer. Or so I've heard.

It drops your seat a little from the lowest-possible stock setting, if you have manual seats.

You can order them from any Recaro dealer.

Jerkin

I'm definitely in need of these... So I call the recaro dealer and ask for an erector set for a c230 coupe?

tommy

Just pick the closest dealer to you, or online (Options Autosport, for example), and have them order the application you need. Hopefully, they still make them for all W203s; I got one for my coupe (driver's side) about 5 years ago or so - it is a separate model than the sedan's.

Jerkin

I know a lot of companies don't make brackets anymore but I guess I can ask recaro for an adapter

Jerkin

Because I was quoted 380 per bracket?

Jerkin

Id love a part number or something because they wanted me to get completely new brackets I think

tommy

380 seems way too steep!

I think that mine was 100-125, tops. Unfortunately, it's been too long since I bought it to still have the part #.

I'd call around at a couple of Recaro dealers, to see what others charge.