1994 BMW 318i Engine harness

640-2



HEATING
AND
AIR
CONDITIONING

3
.
Remove
wiring
harness
retaining
clip
at
bulkhead
.
Re-

move
screws
retaining
wiring
harness
cover
and
pull

cover
forward
.
See
Fig
.
2
.

0012529

Fig
.
2
.
Ming
harness
cover
screws
at
base
ofwindshield
(arrows)
.

4
.
On
passenger
side,
push
aside
wiring
harness
and
re-

move
two
screws
retaining
plenum
housing
.
See
Fig
.
3
.

Fig
.
3
.



Ríghtside
plenum
retaining
screws
(arrows)
.

VU1L535

5
.
On
driverside,
push
aside
wiring
harness
and
remove

screw
retaining
plenum
.
Pull
plenum
up
and
remove
from
engine
bay
.
See
Fig
.
4
.

6
.
Unclip
blower
motor
housing
cover,
disconnect
control

cable,
and
turn
center
retainer
1
/4
turn
to
remove
cover
.
See
Fig
.
5
.

7
.
Disconnect
electrical
connectors
from
blower
motor
.

8
.
Remove
left
upper
section
of
blower
housingby
detach-
ing
spring
clipsat
edge
of
housing
.
See
Fig
.
6
.

HEATER
AND
CONTROLS

Fig
.
4
.



Remove
screw
at
A
and
pull
air
plenumupward
.

0012534

0012636

Fig
.
5
.



Blower
motor
housing
clips
(A)
;
control
cable
(B)
;
and
center
retainer(C)
.

i
[u6,

Fig
.
6
.



Spring
clips
(arrows)
on
driver
sideof
blower
housing
.

9
.
Release
blower
motor
retaining
strap
andremove
blow-
er
motor
and
fans
fromcowl
opening
.

NOTE-

Twist
and
rotate
blowermotor
assembly
to
facilítate
re-
moval
from
opening
.
If
the
blower
motor
is
to
be
rein-stafled,
use
care
not
to
damage
fan
wheels
during
removal
.
ff
the
blower
motor
fs
to
be
replaced,
cut
offfan
wheels
at
center
to
aid
in
removal
.

10
.
Installation
is
reverse
of
removal
.
When
installing
a
re-
placement
blower
motor,
instan
motor
into
cowlarea
before
installing
fan
wheels
.
Blower
motor
test
specifi-

cations
are
listed
in
Table
a
.

NOTE
-

On
replacementblowermotors
from
BMW,
thefan
wheels
come
unattached
to
aid
in
installation
.
Locatearrow
on
blower
motor
and
instan
fan
wheels
atthis
po-
sition
.
Be
sure
color
coolng
matches
.
Retain
fan
wheels
using
the
new
clips
.
See
an
authorized
BMW
parts
de-
partment
for
the
latest
parts
information
.

Table
a
.
Blower
Motor
Test
Values

Testingvoltage



13
VDC

Operating
voltage



9-15
VDC

Max
.
current
consumption
(approx
.)



12
amps

Maximum
speed



3,600-4,000rpm

Axialplay
(max
.
allowable)



1
.0
mm
(0
.04
in
.)

Blower
motor
resistor
pack,
replacing

The
blower
resistor
pack
is
clipped
into
the
upper
left
side
of
theheater
box
.

1
.
Remove
lower
left
dash
trim
panel
.
See513
Interior

Trim
.

2
.
Working
under
left
(driver's)
side
of
dash,
unclip
and

pulí
out
resistor
pack
from
sideof
heater
box
.
Remove

harness
connector
from
resistor
pack
.
See
Fig
.
7
.

3
.
Installation
is
reverse
of
removal
.

Heater
valve,
replacing

The
two-way
heater
valve
is
located
in
the
rear
of
the
engine

compartment
on
the
driver
side
.
The
solenoid
operated
valves

control
the
coolant
flow
through
the
dual-chamber
heater

core
.

1
.
Drain
engine
coolant
.
See
170
Radiator
and
Cooling

System
.

HEATING
AND
AIR
CONDITIONING



640-
3

uuiGO4I

Fig
.
7
.



Blower
fan
resistor
pack
(black
arrow)
and
resistor
pack
re-
ceptacle
(white
arrow)
below
left
sideof
dash
.

WARNING
-

Allow
the
cooling
system
to
cool
before
opening
ordraining
the
cooling
system
.

2
.
Disconnect
hoses
and
harness
connector
at
heater
valve
.
See
Fig
.
8
.

001[ó38b

Fig
.
S
.



Hoses
(A)
and
harnessconnector
(B)
at
heatervalve
.

3
.
Carefully
pull
heater
valve
out
of
rubber
mounting
and

pull
up
and
out
of
engine
compartment
.

4
.
Installation
is
reverse
of
removal
.
Use
new
hose

clamps
.
Inspect
hoses
and
replace
asnecessary
.

HEATER
AND
CONTROLS

640-4



HEATING
AND
AIR
CONDITIONING

Heater
box,
removing
and
installing

The
heater
box,
located
underneath
thecenter
of
the
dash-

board,
houses
theheater
core,
the
A/C
evaporator,
and
asso-

ciated
sensors
and
actuators
.
Removal
of
theheater
box

requires
that
the
A/C
refrigerant
be
discharged
.

CAUTION-

"
Removing
the
heater
box
requires
evacuating
the
AIC
system
.
DO
NOT
attempt
this
procedure
without
proper
tools
and
training
.

"
Any
person
who
services
a
motor
vehicle
air
con-

ditioner
must,
by
law,
be
properly
trained
and
cer-
tified,
and
use
approved
refrigerant
recycling
equipment
.
Technicians
must
complete
an
EPA-
approved
recycling
course
to
be
certified
UU12639

Fig
.
10
.
Heater
core
mounting
nuts
at
left
sideof
bulkhead
(arrow)
.

1
.
Drain
engine
coolant
.
See
170
Radiator
and
Cooling



wiper
assembly
shown
removed
for
clarity
.

System
.

2
.
Remove
complete
dashboard
.
See513
Interior
Trim
.

3
.
Remove
blower
motoras
described
earlier
.

4
.
Remove
nut
retaining
water
hose
flange
to
rear
bulk-
head
.
I'ush
flange
to
one
side
.
See
Fig
.
9
.

Fig
.
9
.



Nut
retaining
coolant
hose
flangeat
bulkhead
(arrow)
.

NOTE-

Clear
any
remaining
coolant
from
the
heater
core
by
blowing
compressed
air
finto
the
coolant
feed
hose
.

HEATER
AND
CONTROLS

0012638b

6
.
Cut
wire
tie
holding
wire
harness
to
heater
box
and
dis-

connect
cable
harness
connector
from
heater
box
.
See

Fig
.
11
.

0012647

Fig
.
11
.
Harness
connectors
(A)
and
cable
tie
(B)
at
heaterbox,
under
driver
side
dash
.

7
.
Followingmanufacturer's
instructions,
connect
ap-

proved
refrigerant
recovery/recycling/recharging
unitto

A/C
system
and
discharge
system
.

8
.
Unbolt
A/C
refrigerantlines
flange
from
engine
bay
bulkhead
.
See
Fig
.
12
.

9
.
On
models
with
rotary-knob
A/C
control
head
:
Discon-
5
.
Remove
nuts
from
heater
box
retaining
bracket
on
en-



nect
wiring
harness
connectors
to
A/C
control
module
gine
bulkhead
left
side
.
See
Fig
.
10
.
Repeat
procedure



in
center
console
and
remove
module
.
See
Fig
.
13
.
for
right
side
nuts
.

640-6



HEATING
AND
AIRCONDITIONING

Heater
core,replacing

1.
Drain
engíne
coolant
.
See170
Radiator
and
Cooling

System
.

WARNING
-

Allow
the
cooling
system
to
cool
before
opening
or
drainíng
the
cooling
system
.

2
.
Remove
center
console
.
See
513
Interior
Trim
.

3
.
Remove
Multi-Information
Display
(MID)
module
.
See

620
Instruments
.

4
.
Remove
lower
dash
panel
and
knee
bolster
on
driver

side
.
See
513
Interior
Trim
.

Fig
.
17
.
Wire
harness
retaining
clips
and
wire
ties
at
heater
box
cover
5
.
Working
under
driver
side
of
dash,
remove
coolant



(arrows)
.
flange
from
heater
core
.
See
Fig
.
16
.

0012651

Fig
.
16
.
Bolts
at
3-way
coolant
flange
under
driver's
side
of
dash
(ar-
rows)
.

NOTE-

Residual
coolant
in
heater
core
will
spill
.
Protect
thecarpet
.

6
.
Working
at
front
of
driveshaft
tunnel,
unclip
wire
har-

nesses
and
move
to
one
side
in
front
of
heater
box
.
See
Fig
.
17
.

7
.
Remove
heatercore
temperature
sensorsas
described

later
in
this
repair
group
.

8
.
Remove
front
heater
box
cover
.
See
Fig
.
18
.

9
.
On
right
side
of
heater
box,
unclip
heater
air
duct
actu-
ating
lever
.
Remove
cross-rod
(with
flaps)
from
frontof
heater
core
.
See
Fig
.
19
.

HEATER
AND
CONTROLS

0012662

Fig
.
18
.
Screws
retaining
front
heater
box
cover
(shown
removed)
to
heater
box
(arrows)
.

0012661
Fig
.
19
.
Pry
heater
flap
actuating
lever
in
direction
A
.
Pull
offair
flap
cross-rod
in
direction
B
.

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

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

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

721-
4



AIRBAG
SYSTEM
(SRS)

CAUTION-

A
new
contact
ring
is
held
in
center
position
with
a
screw
.
This
locking
device
must
be
removed
after
contact
ring
is
installed
on
steering
wheel
.
See
Fig
.
4
.

Latercars
(1994
on)
:

"
Connect
ground
lead
at
contact
ring
.
"
When
installing
a
new
contact
ring
from
BMW,
remove

locking
pin
after
installing
contact
ring
to
steering
wheel
.

See
Fig
.
5
.

Airbag
crash
sensor,
replacing

Fig
.
5
.



Airbag
contact
ring
locking
pin
(arrows),
as
installed
on
new
replacement
part
from
BMW
(later
production
cars)
.
Contact
ring
mountíng
screws
shown
at
A
.

CAUTION-

Anew
contact
ring
is
held
in
center
position
with
a
screw
or
pin
.
This
locking
device
mustbe
removed
after
contact
ring
is
installed
on
steering
wheel
.
See
Fig
.
5
.

The
airbag
system
in
cars
produced
through
1993
uses
two
crash
sensors
mounted
in
the
engine
compartment
on
the
left
and
right
wheel
arches
.
The
sensors
are
identified
by
their
or-
ange
color
.

WARNING
-

If
en
airbag
is
deployed,
both
sensors
must
be
re-
placed
.

1
.
Disconnect
negative
(-)
cable
from
battery
and
cover
negative
terminal
with
insulating
material
.

CAUTION-

Prior
to
disconnectiog
the
battery,
read
the
battery
disconnection
cautíons
given
at
the
front
of
thls
manual
on
page
viii
.

AIRBAG
SENSORS
AND
ELECTRONICS

2
.
Remove
lower
steering
column
trim
mounting
screw
and
remove
lower
trim
.
See
Fig
.
6
.

Fig
.
6
.



Lower
steering
column
retaining
screw
(arrow)
.

3
.
Remove
orange
SRS
connector
from
its
holder
and
carefully
separate
connector
.
See
Fig
.
7
.

Fig
.
7
.



Orange
SRS
connector
below
steering
column
(arrow)
.

4
.
Working
in
engine
compartment,
remove
anti-tamper
Torx
screwsfrom
crash
sensor
.
Remove
sensor
and
disconnect
harness
connector
.
See
Fig
.
8
.

5
.
Installation
is
reverse
of
removal
.
Make
sure
arrow
on
sensor
faces
forward
when
installing
sensor
.

WARNING
-

Once
the
airbag
unit
is
installed
and
all
other
ser-vice
procedures
have
been
completed,
start
the
en-
gine
and
check
that
the
SRS
warning
light
goes
out
.
If
the
warning
light
stays
on,the
SRS
system
will
not
function
as
designed
.
Have
the
system
diagnosed
and
repaired
byen
authorized
BMW
dealer
.

0012543

0011891