Seat Time, Part 3

This is the tale of a lucky find, and also of the way that knowledge seeps away with time, causing once-common knowledge to disappear.  That has always been a big issue in auto restoration, but it will be huge in years to come, when folks are trying to restore electronic systems that were cutting-edge when made, but now obsolete.

I previously posted in Seat Time, Part 1 and Seat Time, Part 2 about my driver's seat, which was stuck in the highest position, putting my head against the roof of the car.  The problem was a broken gearbox in the seat pedestal, and that is not a service item.  I was able to manually adjust the seat to a reasonable position, but all the other faults of the seat remained: torn upholstery, and very hard foam and leather.


There's an app on both iPhone and Android that has been useful a few times: it's called CraigsPro, and it lets you search multiple locations on Craigslist at once.  It even lets you store searches, and the app will notify you when a new post is entered that matches the search.  I have "BMW Z3" stored in the Auto Parts category.

Recently, I got a hit on a complete seat in good condition.  I called, and it was at a speed shop in Maryland down by the BWI airport.  I negotiated a $150 price, and John Zimmerman and I drove down in my Scion xB to pick it up.  When we got there, what we found was not just some speed shop but this:  At Speed Motorports.  There must have been a couple million dollars worth of high-end Porsches sitting around and on one of the half-dozen lifts.  I was so dumbfounded that I forgot to take any pictures, but here's a comparison of some of the damage on the old seat, and of my nice new seat (which had been removed from a Z3 years ago in order to install a racing seat):

The leather on the new seat is actually much better than in that picture - it was just dirty.  And even better, the trip home shook all the change out the seat that the prior owner had lost - a windfall!

Of course, there's always a catch, and this time it was a big one.  The existing seat hooked to the car via a cable with four plugs.  The new seat was from a newer model, and and had a single big plug on the bottom, like this:

My plan was to find something in the parts catalog that would hook to that plug, and then try to adapt it to my existing harness.  But when I searched, I came up with this:

 61106916218 ADAPTER LEAD F ONE-PIECE SEAT PLUG (to 06/00)  $79.03

The drawing was promising - it had a big plug on one end, and several small plugs on the other.  Could this be a factory cable to marry a new seat to the old chassis?  Here's where the "knowledge that seeps away" came into play, because nobody could tell me.  The guys at the dealership didn't know, and even Mike Miller, the BMW club's nearly-omniscient tech adviser didn't know.  Special order parts like this are usually not returnable, but the good folks at the parts department of Faulkner BMW told me that they would allow a return if it didn't fit.  I ordered it, and even got the 10% BMWCCA discount from Faulkner.  Here it is:

Aaaannnddd.... it was almost perfect!  The big plug fit the new seat, and the small connectors seemed to match what I remembered was in the car.  I installed the cable first on the new seat.  Figuring out how to mount that big connector back to the blue clip was a trial - I finally realized the clip comes off with a quarter-turn counter-clockwise, and then you can mount the clip on the plug, and put it all back at once.  When done, I had the seat when a "pigtail" pointing back to mate with the harness in the car:

I wrestled the new seat into the car, and started hooking up plugs.  The two big ones (which I already knew were power plugs) hooked up fine, as did one of the smaller ones, but the other one would not fit, no matter how hard I tried.  Time to figure out what it was.  There were two wires.  One was yellow with a red stripe, and the other yellow with a brown stripe.

I got out my Bentley manual and started poring over the schematics.  I have a lot of experience with that, but I wasn't making heads or tails of it - until I realized: this is a German schematic!  All the color codes are in German, not the ones I learned as a mainframe computer technician 30 years ago.

Google to the rescue, and I found a good chart on http://www.bmw2002faq.com

WIRE COLORS 

English .......................DIN (German) 

Black . . . . . . . . . . . . . . . . . . . . .Sw 

Blue . . . . . . . . . . . . . . . . . . . . . .Bl 

Brown . . . . . . . . . . . . . . . . . . . ....Br 

Green . . . . . . . . . . . . . . . . . . . . ..Gn 

Gray . . . . . . . . . . . . . . . . . . . . . .Gr 

Orange . . . . . . . . . . . . . . . . . . .....Or 

Pink . . . . . . . . . . . . . . . . . . . . . .Rs 

Purple . . . . . . . . . . . . . . . . . . . ...Vi 

Red . . . . . . . . . . . . . . . . . . . . . ..Rt 

Turquoise . . . . . . . . . . . . . . . . . ....Tk 

White . . . . . . . . . . . . . . . . . . . . ..Ws 

Yellow . . . . . . . . . . . . . . . . . . . ..Ge 

So, I needed Yellow (Gelb) with Red (Rot) or Brown (Braun).  Ge/Rt and Ge/Br.

Searched a while, and there they were, two wires going to the Drivers' Side Seat Belt Pyrotechnic Pretensioner.  In other words, the little bomb that goes off in a wreck to yank the seatbelt a little tighter.  I can live without that.  I already had an SRS code from something else, so the airbag system doesn't work anyway.  And I'm just not sure that I want a 15-year-old airbag going off in my face anyway - if that bag split, the explosive gases would cook the skin right off my face.

The great news is that the seat mechanism works perfectly, so I now have a complete, good condition seat that I can actually adjust.  Success!