[W126 Coupe] Seat switch conversion question

Sharan Bains sharanbains at hotmail.com
Fri Sep 23 15:13:29 EDT 2005


Hi Dick,

The wiring loom consists of a few extra wires which link the extra buttons 
on the seat control switch to some extra relays on the seat base frame power 
board. I have also noticed that the non-memory looms running to headrest and 
backrest motors have 2 pins whereas the memory motor connections have 4 
pins. So there is some extra fuctionality at the motors as well.

Note also that the memory function is also linked to the electric steering 
column.

Ideally remove the seats, seat control switches and steering column from the 
300SE. And the wiring looms for the seats - they are a pain to remove 
through the door entry points but other than that dead easy. They run upto 
the fusebox and plug into points a and b.

Then remove the seats from your SEC and simply transfer the base frames from 
your 300SE seats to your SEC seats and transfer the backrestmotor set-ups 
into your SEC backframe....all you need to do is remove the backrest leather 
cover on both seats and change the internal motors and looms.

You'll need to remove the SEC seat switch looms and run in the SE seat looms 
of course and change the seat control switches.

Finally the steering column - it is a DIRECT fitment into your early SEC, 
with only one modification required. The metal firewall that the column 
bolts upto just beneath the dash has an extra side curving that just needs 
to be grinded away. The column then bolts upto directly. Simple job - remove 
the 6mm allen key at the steering box, 3 10mm bolts at the centre of the 
column and 2 13mm bolts just under the instrument cluster.

Sounds like a lot of work, but it's easily feasible in one weekend. You'll 
then have memory seats, memory and electric steering column. The combination 
indicator and cruise switch also needs to be changed over as the electric 
steering column switch has a longer loom.

Basically a change of looms, motors and switches, but very valuable 
upgrades...and all in a weekends work.


talbir


>From: "Dick Spellman" <spell.yy at verizon.net>
>Reply-To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>
>To: <mbcoupes at mbcoupes.com>
>Subject: [W126 Coupe] Seat switch conversion question
>Date: Fri, 23 Sep 2005 12:52:59 -0400
>
>I have an 83 SEC with the passenger door seat control needing replacement.  
>In 83 there was no seat memory button and the wiring harness was soldered 
>directly to the switch.
>
>I have a 90 300SE parts car now with both memory seat switches working.  
>Does anyone know if the memory switch is interchangeable with the 
>non-memory switch and if so anything special about wiring or fit I need to 
>look at?
>
>Many thanks,
>
>Dick Spellman


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