From dale_at_unofficialbmw.com Mon Dec 7 12:18:57 1998
by mail.eskimo.com (8.9.1a/8.8.8) with ESMTP id MAA21574;
Mon, 7 Dec 1998 12:18:52 -0800 (PST)
Date: Mon, 07 Dec 1998 12:15:11 -0800
From: Dale Beuning <dale_at_unofficialbmw.com>
To: jim.powerll_at_ada.com, dale_at_unofficialbmw.com
Subject: heated seat install
I don't know if you've done your heated seat install yet, but here is
someone sent me that may be useful to you.
'95 M3 - heated seats from the factory, can't feel it through the
Heated seats install. (Xmas 1997)
As many of you wrote me with questions on heated seats install on E36,
well - here it is. I finally got around to it. Here is the summary:
Difficulty index: Keg of beer (no kidding)
Tools needed: Assorted screw drivers
Assorted ratchet wrenches
Torx drivers (size 10 & 20)
Pliers, multi-meter, patience of steel
I purchased the kit (52 11 94 02 814) from a BMW dealership in Germany
for 432 DM and it included heat elements, wiring harness, relay, fuse,
console switches, assorted hooks and fasteners, and installation
The installation can be broken down into 3 phases: installing the
wiring harness, reupholstering the seats, drinking beer. I will go
through each phase and describe the problems I've encountered. I would
also like to add that this write up is for entertainment purposes only.
I'm not encouraging anybody to do this again. It's a bitch. It sucks.
It totally makes your weekend miserable. It hurts. (Yup, blood index
The wiring harness, once untangled and straightened out, is pretty
simple to figure out. Two connectors per seat to the heating elements,
two connectors to the console switches, connector for relay, branch
point for heated mirrors (I'm guessing), console switches illumination
leads, ground lead, power (fuse lead), fan output lead. Only the last
two leads must be brought over into the engine compartment to the fuse
To start, the paneling under the steering wheel must be removed, the
dead pedal/speaker panel must also be removed. This exposes the wiring
harness that punches through the firewall to the fuse box. There are 4
bolts that must be removed to loosen up the fuse box. Two of the bolts
are visible, 3rd one is hidden behind the wiring harness, and the 4th
one, well, I never found the 4th one. Next, the fuse box top portion
must be unscrewed. The 4 torx size 10 screws are a bitch to remove -
especially the two by the firewall. The top of the box pops up and all
the wiring going to the fuse box can be pulled away. The problem is
that the wiring is so tight that you don't get much leeway. Next, a
special clamp has to be removed which loosens up the 3" thick wad of the
wiring harness that goes inside the car. Since I couldn't find the 4th
bolt, I couldn't get the clamp out far enough and I couldn't loosen up
the harness. I decided to try to poke through each lead wire at a time
and finally got the two wires through. Yeah!! Beer break. Next, the
fuse holder for that one specific fuse has to pop out, (looks much
easier on the instruction sheet.) Once the holder is out, insert in
the leads, (one from the harness, one short piece which was also
provided) snap in back into the fuse box, and insert the fuse. Easy.
At that point I had 2 wires (red and green) which instruction manual
said to insert into branch point X0030 and X0015, Hmmm.... this must be
where the "specialized knowledge" that the instruction sheet mentioned
comes in. After scratching my head for 30 minutes I decided to stick my
hand into the glob of wires at the bottom of the lower part of the fuse
box. Lo and behold, there are approx. 30 different branch points hiding
inside. After examining each and everyone, I did not find anything with
X0030 and X0015 markings. There were no 'X' markings at all! Enough.
Beer break. At that point I decided to move inside the car and finish
wiring up the rest. Ground lead wire is easy. The relay attaches to
one of the snap-in places on a distribution box, easy. Branch point for
the heated mirrors snaps in the distribution box, easy. The
illumination lead wires go into a branch point X0045. Hmmm... Here we
go again. No sign of X0045 in the distribution box. Another beer.
Believe it or not, that last bottle of beer, illuminated a new neuron
passage in my brain and I suddenly started seeing things... Each
branch point connector has all wires of the same color. All I have to
do is find the right color combination and insert my switch illumination
leads into it. I tested my theory with the ignition key on and
headlights on. Yup. Switches light up. Bingo! More beer. It
actually helps. Now I was able to find the correct branch points in the
fuse box and finish up under the hood.
At this point I fished-through the console switch cables. Easy job.
Just pull to the side the leather around the shift knob, punch out two
blank plastic pieces where the switches go, pull through the cables,
snap in the switches. Basically 50% chance of getting them right. Of
course - I chose poorly.
Next, I started disassembling the glove box and the speaker side cover.
Since I've already removed the glove box at least 5 times in the short
life of my car, it took 3 minutes. Now fish through the passenger side
element connectors, tie wrap the wiring to the main harness, and swing
another bottle of beer. At this point I was ready to pull out the
seats. Yes, that's what the manual says. It also says to pull up the
carpeting. Taking the seats out actually turned out to be the easiest
part of the job. Just position the seat such that all 4 bolts are
visible, raise the seat to the max, unplug all the connectors, remove
the four mounting bolts and voila... slowly remove the seat out of the
car. The sucker is about 100 lbs. so watch your back.
Now that you've got the seats inside the house, the fun begins. The
disassembly of the seat is quite straight forward, although it is very
time consuming. Starting with the bottom seat cushion, there are 2 or 3
hex screws and 2 plastic studs/bolts holding the cushion to the frame of
the seat. The bolts are reusable (the kit comes with 5 or six new ones)
so you just push it out or snap it out and the whole seat cushion can be
flipped over. My sport seat has a kind of extender in the front, which
makes it impossible to separate it completely from the frame. But
that's OK, you just flip the cushion over and start unhooking the hide.
Once the hide is unhooked all around, there are little metal hooks that
attach the hide to the foam insert. This is where your patience is
really tested. Each hook must be unclamped and/or snipped off with the
cutters (there are new hooks also provided with the kit, but not enough
for the whole job) and slowly work your way until the leather hide is
separated from the foam cushion. Now just place the heated element on
the foam, align the holes and start the hook process in reverse. Yes,
it's a tidious task, but it can be done. Once the leather is back on,
insert new plastic bolts (removing the broken off bolts from the seat
cushion is also a bitch) and snap the cushion back in the frame.
The back cushion is a bit easier. Remove the 2 hex screws, remove the
side levers and the back plastic just comes off. Now you can remove the
back cushion completely from the frame and start the unhooking/hooking
process all over again.
The big problem that I faced was that the heated elements were not the
right type for my seats. I have sport seats and the elements were
probably for the regular seats. Fortunately I was able to cut few holes
in the fabric, making sure I don't cut the element and proceed with the
job. I'm not sure why I got the wrong kit. Perhaps the kit was put
together wrong, because I watched the German BMW parts guy as he
scrolled through his CD-ROM parts fiche. Oh well.
And now for the final stage of the job - getting the element connectors
under the seats. There is really one correct way of doing this. You
remove the bottom long plastic piece of trim, pull up the carpet and
fish the cable through the hole in the carpet under the seats.
Unfortunately I had no clue whatsoever how to remove the side trim
piece. Again, the specialized knowledge comes into play. I finally
figured it out, breaking a few clamps in the process. I pulled the
cable through and now couldn't figure out how to get the trim piece back
on. The plastic 'snaps' were still in the frame of the car and they
didn't appear to be willing to get out. After chugging a few beers I
decided to order
a new trim piece and ask BMW service how to get it back on.
Now as far as the other (passenger) side is concerned, I cheated a bit.
I didn't want to destroy another piece of trim, so I decided to make a
small incision in the carpet (from the side of the trim piece to the
vent outlet under the seat), run the cable under the trim piece and
inside the carpet 'cut.' I figured, once I put the seat back on, and
attach the plastic side piece there will only be about an inch of the
'cut' visible. I was right. You can't even tell the cut is there,
unless you run your finger over it.
So now you can put the seats back on, tighten the bolts, get all the
connectors lugged in and attach the plastic side piece. Done.
If there is any beer left, by all means - finish it off. I tested the
seats and after realizing that driver side switch turns on the passenger
seat, I swapped the switch connectors and everything was working good.
BMW CCA #135536