1993 BMW M3 Electric

640-10



HEATING
AND
AIR
CONDITIONING

i

El
Radio

Antenna

Rear



.
,



si,-
Left
side



I
d

1
.
Rear
vents
2
.
Fresh
air
3
.
Face-level
vents
4
.
Recirculation
5
.
Footwell
vents
0013017

Fig
.
28
.
Location
oflate
production
air
distribution
motors
in
heater
box(shown
in
rear,
side
and
top
views)
.

Heater
andA/C
air
distribution
motor,

replacing
(rotary-knob)

1
.
Toaccess
left
side
motors
(dash
vent
mixing
or
recircu-

lation
flap),
remove
lower
dash
panel
and
knee
bolster

on
driver
side
.
See
513
Interior
Trim
.

2
.
To
access
right
side
motor
(fresh
air
flap),
remove
glove

compartment
.
See513
Interior
Trim
.

3
.
Each
motor
can
be
removed
after
its
electrical
wiring

harness
connector
has
been
removed
.
Squeeze
plastic

clip
to
release
motor
.
See
Fig
.
29
.

Fig
.
29
.
A/
C
air
distribution
motor
plastic
retaíning
clip
(arrow)
.
Re-
lease
clip
and
tilt
motor
out
of
housing
.

Rear
Window
Defogger

0011877

The
rear
window
defogger
switch
is
integrated
with
the
heating
andA/C
control
head
.

HEATER
AND
CONTROLS

Fig
.
30
.
Wiring
diagram
of
rear
window
defogger
and
radio
antenna
.

Rear
Window
Blower
(Convertible
Models)

A
blower
fan,
fitted
into
the
rear
seatback,
defogs
therear

window
.
It
will
only
operate
with
the
engine
nunning
and
the

top
raised
.
A
microswitch
behindthe
rear
seats
provides
the

signal
that
thetop
is
raised
.

To
access
the
blower
fan
motor,
it
is
necessary
to
remove

four
screwsfrom
the
center
seat
back
.
Remove
the
wiring
har-

ness
connector
and
motor
mounting
boits,
then
remove
motor

by
pulling
it
down
and
forward
.
See
Fig
.
31
.

ri

Suppressor
filter

1
0013005

Fig
.
31
.
Rear
window
blower
in
center
of
rear
seat
back
(arrow)
.

The
electric
rear
window
defogger
is
integrated
with
the
ra-

dio
antenna
.
See
Fig
.
30
.



y



/f



0013014

To
access
the
rear
window
blower
relay,
remove
the
glove
compariment
.
See
Fig
.
32
.

Fig
.
32
.
Rear
window
blower
relay
located
in
frontof
glove
compart-
ment
(arrow)
.

AIR
CONDITIONING

Thissection
covers
removal
and
installation
of
air
condition-

ing
refrigerant
components
.
A/C
testing
and
diagnosis,
refrig-

erantdischarge,
evacuatíon
and
recharge
are
not
covered

here
.

The
subassemblies
and
lines
of
the
air
conditionerare
filled

with
either
refrigerant
R12
(1992
cars)
or
R-134a
(1993
and

later
cars)
.
The
major
components
of
the
A/Csystem
are

shown
in
Fig
.
33
.

A/CSystem
Warnings
and
Cautions

WARNING
-

"
Always
be
careful
that
refrigerant
does
not
come
in
contact
with
your
skin
.
Always
wearhand
andeye
protection
(gloves
and
goggles)
when
work-

ing
around
the
AIC
system
.
If
refrigerant
does
come
in
contact
with
your
skin
oreyes
:
-Do
not
rub
skin
oreyes
;

-Immediately
flush
skin
oreyes
withcool
water
for
15
minutes
;
-Rush
to
a
doctor
orhospital
;
-Do
not
attempt
to
treat
yourself
.

"
Work
in
a
wefl
ventilated
area
.
Avoid
breathing
re-
frigerant
vapors
.
Exposure
may
irrítate
eyes,

nose,
and
throat
.
Switch
on
exhaustlventilation
systems
when
working
on
the
refrigerant
system
.

"
Do
not
expose
any
component
of
the
AIC
system
to
high
temperatures
(Above
80°Cl176°F)or

open
flames
.
Excessive
heat
will
cause
a
pres-

sureincrease
whichcould
burst
the
system
.

HEATING
AND
AIR
CONDITIONING



640-
1
1

0013015

WARNING
-

"
Keep
refrigerant
away
from
open
llames
.
Poison-
ous
gas
will
be
produced
if
it
bums
.
Do
not
smoke
near
refrigerant
gases
for
the
same
reason
.

"
The
AICsystem
is
filled
with
refrigerant
gas
which
is
under
pressure
.
Pressurized
refrigerant
in
the
presenceof
oxygen
may
forma
combusti-
ble
mixture
.
Never
introduce
compressed
air
finto
any
refrigerant
container
(full
or
empty),
capped
off
AIC
component,
or
piece
of
service
equip-
ment
.

"
Refrígerant
gases
are
heavier
than
air,
displace
oxygen
and
may
cause
suffocation
in
areas
of
poor
círculation,
for
example
under
a
car
.
Switch
on
exhaustlventilation
systems
when
working
on
the
refrigerant
system
.

"
State
and
local
governments
may
have
additional
requirements
regarding
air
conditioning
servic-
ing
.
Alwayscomply
with
state
and
local
laws
.

"
Electric
welding
near
refrigerant
hoses
causes
R-134a
to
decompose
.
Discharge
system
before
welding
.

CA
UTION
-

-As
of
January
1,
1992,
any
person
who
services
a
motor
vehicle
air
conditioner
must,
by
law,
be
properly
trained
and
certified,
and
use
approved
refrigerant
recycling
equipment
.
Technicians
must
complete
an
EPA-approved
recycling
course
to
be
certified
.

"
It
is
recommended
that
al¡
system
refrigerant
AIC
refrigerant
be
left
to
an
authorized
BMW
dealer
or
other
qualified
AIC
service
facility
.

"
Do
not
top
off
a
partially
charged
refrigerant
sys-
tem
.
Dischargesystem,evacuate
and
then
re-
charge
system
.

"
R-134a
and
R-12
refrigerants
and
refrigerant
oils
and
system
components,
including
hoses
and
sealing
O-rings,
are
NOT
compatible
.
Compo-
nent
damage
andlor
system
contamination
will

result
.

"
The
mixture
of
refrigerant
oil
(PAG
oil)
and
refrig-
erant
R-134a
attacks
some
metals
and
alloys
(for
example,copper)
and
breaks
down
certain
hose
materials
.
Use
only
hoses
and
lines
that
are
iden-
tified
with
a
green
mark
(stripe)
or
the
lettering
R-
134a"
.

"
Immediately
plug
open
connections
on
AIC
com-
ponents
to
prevent
dirt
and
moisture
contamina-
tion
.

"
Do
not
steam
clean
condensers
or
evaporators
.

Use
only
cold
water
or
compressed
air
.

AIR
CONDITIONING

Fig
.
36
.
6-cylinder
engine
belt
diagram
:
To
remove
A/C
belt,
lever
ten-
sioner
(A)
in
clockwise
direction
using
long-handled
wrench
or
breaker-bar
.

6
.
Disconnect
electrical
harness
connector
from
com-
pressor
.

7
.
Remove
A/C
pressure
hose
and
suction
hose
flange



10
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
bolts
from
compressor
.
Plug
hoses
immediately
See



Recharge
system
following
equipment
manufacturer's

Fig
.
37
.



instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

0011879

Fig
.
37
.
A/
C
compressor
pressure
hose
(A)
and
suction
hose
(B)
.
(6-
cylinder
engine
shown
.
4-cylinder
engine
is
similar
.)

HEATING
AND
AIR
CONDITIONING



640-
1
3

Fig
.
38
.
A/
C
compressor
mounting
boits
(arrows)
.

9
.
Installation
is
reverseof
removal
.

CAUTION
-

"
Always
replaceO-rings
when
reconnecting
re-
frigerantfines
.

"
When
installlng
a
new
compressor
always
re-
place
receiverldrier
unit
.

Tightening
Torques

"
A/C
compressor
to
engine
block
....
22
Nm
(17
ft-Ib)
"
A/C
line
flange
to
A/C
compressor
5/8
in
.
fine
.
......
.....
....
.
.....
20
Nm
(15
ft-Ib)

3/4
in
.
fine
.......
.....
..........
39
Nm
(29
ft-Ib)

7/8
in
.
fine
...
....
.....
..........
42
Nm
(31
ft-Ib)

11/16
in
.
fine
.....
..
..
..
...
.
.....
48
Nm
(35
ft-Ib)

A/C
Compressor
Clutch

The
compressor
clutch
can
be
replaced
without
disturbing

thesealed
refrigerant
system,
although
clearances
in
the
six-

cylinder
cars
may
be
very
tight
.
Detach
the
compressor
from

the
compressor
bracket
togain
extra
clearance
.

8
.
Remove
compressor
mounting
boits
.
See
Fig
.
38
.
Re-



Typical
A/C
compressor
and
clutch
is
shown
in
Fig
.
39
.
move
compressor
by
pulling
downward
from
under-

neath
car
.



Remove
driveplate
and
pulley
to
access
clutch
magnetic

winding
.
See
Fig
.
40
.

AIR
CONDITIONING

640-14



HEATING
AND
AIR
CONDITIONING

7
Fig
.
39
.
A/
C
compressorand
clutch
components
.

8
00871208

1.
Clutch
plate
retaining
bolt



5
.
A/C
compressor
pulley
2
.
Clutch
plate



6
.
Clutch
retaining
circlip
3
.
Pulley
retaining
circlip



7
.
Clutch
(magnetic
winding)
4
.
Clutch
bearing



8
.
Compressor

00870082

Fig
.
40
.
A/
C
compressor
driveplate
canbe
held
stationary
with
strap
toolto
allow
removal
of
retaining
bolt
.

NOTE-

BMWs
are
equipped
with
compressors
from
various
manufacturers
.
Special
tools
may
be
required
tore-
move
driveplate
orpulley
.

AIR
CONDITIONING

Tightening
Torque

"
Compressor
clutch
bolt

to
compressor
shaft
.....
.
....
..
.
.
20
Nm
(15
ft-Ib)

A/C
condenser,
replacing

1
.
Following
manufacturer's
instructions,
connect
an
ap-

proved
refrigerant
recovery/recycling/recharging
unitto

A/Csystemand
discharge
system
.

WARNING
-

Do
not
dischargelcharge
the
AIC
system
without
proper
equipment
and
training
.
Damage
to
the
vehi-
cle
and
personal
injury
may
result
.

2
.
Remove
front
bumper
and
radiator
grilles
.
See510
Ex-

terior
Trim,
Bumpers
.

3
.
Remove
auxiliary
electric
radiator
fan
.
See
170
Cool-
ing
System
.

4
.
DetachA/C
lines
from
lower
right
corner
of
condenser
.

Plug
lines
immediately
.
See
Fig
.
41
.

Fig
.
41
.
A/
C
flange
bolts
at
condenser
(arrows)
.

5
.
Remove
condenser
mounting
bolts
from
frontradiator

support
.
See
Fig
.
42
.

6
.
Lift
up
condenser
to
disengage
from
lower
mounts
and

remove
from
below
.

7
.
Installation
is
reverse
of
removal
.

CA
UTION-

"
Always
replace
O-rings
when
reconnecting
re-
frigerant
fines
.

"
When
installing
a
new
condenser
always
replace
receiverldrier
unit
.

Fig
.
42
.
Upper
A/C
condensermounting
bolts
(arrows)
.

8
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
Recharge
system
following
equipment
manufacturer's
instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

A/C
receiver/drier,
replacing

The
A/C
receiver/drier
is
mounted
in
the
front
right
cornee
of
the
engine
compartment
behind
the
headlight
assembly
.

CAUTION-

The
receiver/drier
must
be
replaced
when
-There
is
dirt
in
the
AIC
system
-The
compressor
has
seized
or
has
been
re-
placed
for
any
reason
-The
condenser
or
evaporator
are
replaced
for
any
reason
-The
AIC
system
is
leaking
and
there
is
no
more
refrigerant
-The
AIC
system
was
open
for
24
hours
or
more
.

1
.
Following
manufacturer's
instructions,
connectan
ap-

proved
refrigerant
recovery/recycling/recharging
unit
to

A/C
system
and
discharge
system
.

2
.
Remove
right
headlight
assembly
.
See
630
Exterior
Lighting
.

CAUTION-
3
.
Disconnect
A/C
electrical
harness
connectors
.
See
Fig
.



Always
replaceO-rings
when
reconnecting
refrig-
43
.



erant
lines
.

4
.
Remove
refrigerant
pressure
lines
from
receiver/drier
.

Plug
lines
immediately
.

5
.
Remove
receiver/drier
mounting
bolts
.

0013182

6
.
Remove
underbody
splash
shield
on
passenger
side
.

See
Fig
.
44
.

7
.
Remove
passenger
side
brake
cooling
duct
.
Discon-

nect
outside
temperature
sensor
harness,
if
applicable
.

HEATING
AND
AIR
CONDITIONING



640-15

0012669

Fig
.
43
.
A/
C
receiver/drier
electrical
harness
connectors
(A),
pressure
line
retaining
bolts
(B),
andmounting
bolts
(C)
.

0012668
Fig
.
44
.
Passenger
sidesplash
shield
retaining
screws
(arrows)
.

8
.
Push
receiver/drier
down
andremove
from
underneath
car
.
Make
sure
that
receiver/drier
is
clear
of
any
electri-
cal
harnesses
.

9
.
Installation
is
reverse
of
removal
.

10
.
Before
recharging,
evacuate
system
for
at
least
30
min
.

Recharge
system
following
equipment
manufacturer's

instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

AIR
CONDITIONING

CAUTION
-

Always
replace
O-rings
when
reconnecting
refrig-
erant
fines
.

9
.
Before
recharging,
evacuate
system
for
at
least
30
min
.
Recharge
system
following
equipment
manufacturer's
instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

A/C
evaporator,
removing
and
installing

1
.
Followingmanufacturer's
instructions,
connectanap-proved
refrigerant
recovery/recycling/recharging
unit
to
A/C
system
and
discharge
system
.

2
.
Remove
complete
heater
boxas
described
earlier
.

3
.
Remove
expansion
valve
as
described
earlier
.

4
.
Unfasten
evaporator
sensor
electrical
harness
connec-
tor
and
puli
out
sensor
from
ieft
side
of
heater
box
.
See
Fig
.
50
.

Fig
.
49
.
Pull
out
evaporator
sensor
from
housing
in
direction
of
arrow
.

5
.
Remove
rear
heater
box
cover
.

6
.
Remove
clips
retaining
lower
evaporator
housingcover
.
Tilt
outheater
core,
then
pull
evaporator
out
of
housing
.

7
.
Installation
is
reverse
of
removal
.

CAUTION
-

Always
reptace
O-rings
when
reconnecting
refrtg-
erant
fines
.

8
.
Before
recharging,
evacuate
system
for
at
least
30
min
.

Recharge
system
following
equipment
manufacturer's
instructions
.
See
Table
d
.
A/C
System
Refrigerant

Capacities
.

HEATING
AND
AIR
CONDITIONING



640-17

8
.
Installation
is
reverse
of
removal
.



A/C
evaporator
temperature
sensor,

replacing

ou12b46

The
evaporator
temperature
sensor
is
mounted
in
the
left
(driver)
side
of
theheater
box
behind
thecenter
console
.

1
.
Remove
lower
dash
panel
and
knee
boister
on
driver
side
.
See
513
Interior
Trim
.

2
.
Remove
left
footwell
ventilation
duct
byremoving
re-
taining
rivet
in
bottom
of
duct
.
Pull
it
down
and
away
from
heater
box
.
See
Fig
.
50
.

Fig
.
50
.
Left
footwellventilatíon
duct
(arrow)
.

0o1300ba

3
.
Disconnect
sensor
electrical
connector
from
heater
box
.
Pull
sensor
straight
out
of
heater
box
.
Refer
to
Fig
.
49
.

4
.
Installation
is
reverse
of
removal
.
Table
c
.
lists
evapo-

rator
temperature
sensor
test
values
.

Tablec
.
Evaporator
Temperature
Sensor

Test
Values

Test
temp
.



Resistance

23°F
(-5°C)



11
.4
-11
.9
k
ohms

32°F
(0°C)



8
.8
-
9
.2
k
ohms

41
°F
(5°C)



6
.8
-
7
.2
k
ohms

50°F
(10°C)



5
.3-5
.6
k
ohms

59
°
F
(15°C)



4
.2
-4
.5
k
ohms

68°F
(20°C)



3
.3
-
3
.6
k
ohms

77°F
(25°C)



2
.6-2
.9
k
ohms

86°F
(30°C)



2
.1
-
2
.3
k
ohms

95°F
(35°C)



1
.7
-1
.9
k
ohms

AIR
CONDITIONING

650-2
RADIO

"
A
320-watt
Harmon-Kardon
ten
speaker
system,
including



RADIO
AND
SPEAKER
SERVICE
a
separate
high
power
multi-channel
audio
amplifier
and
two
sub-woofers
.
In
this
system,
thebass
and
volume
out-

puts
from
the
selected
audiosource
automatically
com-



Radio,
removing
and
installing

pensate
for
vehicle
speed,
making
constant
volume

adjustments
unnecessary
.
An
additional
feature
ofthis



CAUTION-
sound
system
is
the
ability
to
switch
from
normal
left-right



"
Before
beginning
work
on
the
radio
or
sound
stereo
into
Spatial
Enhancement
Mode,
which
produces
a



system,
verify
that
the
radio
is
an
original
equip-
fuller,
rounder
sound
.
See
Fig
.
3
.



ment
BMW
radio
and
that
thewiring
harness
has
not
been
modified
.
TheE36
radio
is
also
equipped
with
a
built-in
anti-theft
sys-

tem
.
lf
power
is
removed
from
the
radio
circuitry
by
removing

the
radio
electrical
connectors,
or
by
disconnecting
the
bat-
tery,
the
radio
is
rendered
inoperative
.
The
radio
is
not
perma-

nently
damaged,
and
proper
operation
can
be
restored
by

entering
the
radio
anti-theft
code
.

Fig
.
3
.
Ten
speaker
sound
system
.

RADIO
AND
SPEAKER
SERVICE

"
Servicing
of
aftermarket
sound
equipment
should
be
referredto
an
authorized
agent
of
the
equip-
ment's
manufacturer
.

"
Do
not
remove
radio
or
disconnect
the
batterywithout
first
obtaining
the
anti-theft
code
.

1.
Carefully
pry
open
small
square
covers
at
left
and
right

sides
of
radio
.

650-
4
RADIO

3
.
Remove
speakerby
removing
mountingscrews
.
See

Fig
.
8
.

Fig
.
8
.



Speaker
mounting
screws
(arrows)
.

0012580

4
.
Disconnect
harness
connector(s)
from
speaker
.
See

Fig
.
9
.

001,58

Fig
.
9
.



Disconnect
speaker
electrical
connector(s)
in
direction
shown

(arrows)
.

5
.
Installation
is
reverse
of
removal
.

Right
footwell
speaker,

removing
and
installing

1
.
Remove
glove
compartment
lower
trim
.
See
Fig
.
10
.

2
.
Rotate
speakercover
plastic
retainer
1
/a
turn
.
Remove

door
sea¡at
edge
of
speaker
cover
.
See
Fig
.
11
.

3
.
Pul¡
speaker
trim
panel
away
from
body
and
then
pul¡

panel
back
toward
rear
of
car
.

RADIO
AND
SPEAKER
SERVICE

0012582

Fig
.
10
.
Remove
lower
glove
compartment
trim
panel
retaining
screw

(black
arrow)
.
Pull
trim
in
direction
shown
(white
arrows)
.

0012583

Fig
.
11
.
Speaker
cover
retainer
(black
arrow)
.
Pulltrim
in
direction
shown
(white
arrow)
.

4
.
Remove
speaker
by
removing
mountingscrews
.
Dis-

connect
harness
connector(s)
from
speaker
.

5
.
Installation
is
reverse
of
removal
.