engine BMW M3 1994 E36 Workshop Manual

400-
6
BODY-GENERAL

Heating
and
Air
Conditioning

The
electronically
controlled
heating
and
air
conditioning

systemusesan
extra
large,
infinitely
variable
radial
blower
motor
for
good
distribution
of
air
.
Fresh
air
enters
through
the
grille
below
the
engine
hood
and
finto
the
passenger
compart-
ment
via
the
dashboard
and
footwell
vents
.
See
Fig
.
5
.

Repair
information
for
the
heating
and
air
conditioning
sys-

tem
is
covered
in
640
Heating
and
Air
Conditioning
.

Fig
.
5
.



Heating
and
air
conditioning
ventilation
plan
.

INTERIOR
EQUIPMENT

GENERAL

This
repair
group
covers
replacement
of
the
front
fenders

and
removal
and
installation
of
the
engine
hood
.

NOTE-

The
body
is
painted
at
the
factoryafter
assembly
.
Re-
alignment
of
body
panels
may
expose
unpainted
metal
.

Paint
all
exposed
metal
once
the
work
fs
complete
.

FRONT
FENDERS

Front
fender,
removing
and
installing

1
.
Raise
hood
.
Raise
and
safely
support
front
of
vehicle
.

WARNING
-

"
When
raising
thecar
using
a
floor
jack
or
a
hy-

draulic
lift,
carefully
position
the
jack
pad
to
pre-

vent
damaging
thecar
body
.
A
suitable
liner
(wood,
rubber,
etc
.)
should
be
placed
between
the
jack
and
the
car
to
prevent
body
damage
.

"
Watch
the
jack
closely
.
Make
sure
it
stays
stable
and
does
not
shift
or
tilt
.
As
the
car
is
raised,
the

car
may
roll
slightly
and
the
jack
may
shift
.

2
.
Remove
front
wheel
.
Remove
inner
plastic
liner
from

wheel
well
.

3
.
Remove
front
bumper
.
See510
Exterior
Trim,

Bumpers
.

4
.
Working
atfront
corner
of
fender,
remove
front
grille

panel
bolts
(2
bolts
at
left
and
right)
.
See
Fig
.
1
.

FENDERS,
ENGINE
HOOD



410-1

410
Fenders,
Engine
Hood

GENERAL
...............
.
.
.
.
.
.
.
.
.
.
.
..
410-1



ENGINE
HOOD
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
...
.
.410-3

Hood,
raising
to
service
position
.
.
.
.
.
.
.
.
...
410-3
FRONTFENDERS
........
.
.
.
.
.
.
.
.
.
.
.
.
.410-1



Hood,
removin



and
installin



410-3

Front
Pender,
removing
and
installing
.
.
.
....
410-1



Hood,
aligning
...
.
.
.
.
.
.
.
.....
.
.
.
.
.
.
.
...
410-4

Hood
release
cable
and
latches,
adjusting
...
410-4

001
.145

Fig
.
1
.



Front
grille
panel
to
front
fender
retaining
bolts
(arrows)
.
Front

bumpershown
removed
.

5
.
Remove
front
turn
signalliens
assembly
from
applica-

ble
front
corner
.
Carefully
pryout
side
directional
from

fender
(later
cars
only)
.
See
630
Exterior
Lighting
.

6
.
Remove
fender
attaching
bolts
atfront
underside
of

fender
.
See
Fig
.
2
.

7
.
Remove
bolts
along
top
edge
of
fender
:
See
Fig
.
3
.

8
.
Open
front
door
and
remove
fender
mounting
bolts
in

door
jamb
.
See
Fig
.
4
.

9
.
Carefully
remove
fender
from
body
.

FRONTFENDERS

410-2



FENDERS,
ENGINE
HOOD

Fig
.
2
.



Fender
attaching
bolts,
lower
front
(arrows)
.

Fig
.
3
.



Loosen
bolt
A
at
top
offender
.
Remove
bolts
B
.

FRONTFENDERS

0013104
0013105
0013106
Fig
.
4
.



Front
fender
attaching
bolts
as
viewed
through
doorjamb
(ar-
rows)
.

10
.
Installation
is
reverse
of
removal,
noting
the
following
:

"
Before
installing
new
fender,
clean
old
sealant
and
pro-
tective
coating
from
mounting
surfaces
.

"
Position
new
fender
and
loosely
install
all
mounting
bous
.
Align
fender
with
door
pillar
and
front
panel,

then
tighten
bolts
.
"
Repair
any
paint
damage
and
paint
any
exposed
met-
al
.

"
Reseal
and
apply
protective
coating
to
mounting
sur-
faces
.

Clearance
Specification

"
Fender
to
front
hood
or
to
door
.
...
5
.5
mm
(0
.216
ín)

ENGINE
HOOD

Hood,
raising
to
service
position

CA
UTION-

Do
not
switch
on
the
windshield
wipers
wlth
the
engine
hood
raised
.
As
a
precaution,
remove
the
wiper
motor
fuse
.
See
610
Electrical
Compo-
nent
Locations
.

1
.
4-door
models
:
Open
hood
fully
.
Remove
bolt
from

hood
hinge
behind
hood
supports
(left
and
right)
.
Raise
hood
to
service
position
.
See
Fig
.
5
.

2
.
2-door
models
:
Open
hood
fully
.

Fig
.
5
.



Hood
support
bracket
boltto
be
removed
(A)
on
4-door
cars
.

Remove
bolts
at
left
and
right
hinges
.
Swing
bracket
in
direc-
tion
of
arrow
to
raise
hood
into
service
position
.

"
Remove
ground
cable
atright
hood
hinge
.

"
Whilean
assistant
supports
hood,
detach
both
hood

supportsfrom
hood
.

"
Remove
detent
screws
at
back
of
hood
hinges
.
See

Fig
.
6
.
"
Lift
hood
while
pulling
hinge
forward
.
Support
hood
at

higher
position
.

3
.
When
service
work
is
complete,
return
hood
to
lower

position
and
instaf
screws
or
bolts
.

FENDERS,
ENGINE
HOOD



410-
3

Fig
.
6
.



Torx
screw
at
base
of
hood
hinge
(arrow)
.

Hood,
removing
and
installing

0013147

1
.
Raise
hood
.
Where
applicable,
partially
remove
hood

acoustic
insulation
to
access
rear
of
hood
.
See
Fig
.
7
.

Fig
.
7
.



Hood
insulation
retainer
being
pried
out

3
.
Detachgas-charged
hood
supportsfrom
hood
.

CAUTION
-

The
hood
is
heavy
.
Before
removing
the
hood
sup-
ports
or
hood
retainingbolts,
be
sure
to
have
an
assistant
help
support
the
hood
.

0013148

2
.
Disconnect
washer
fluid
hoses
from
washer
nozzles
.

Where
applicable,
disconnect
electrical
harness
con-

nectors
fromheated
nozzles
.

ENGINE
HOOD

410-4



FENDERS,
ENGINE
HOOD

4
.
With
aid
of
assistant,
remove
hood
hinge
bolts
from
left

and
Rght
sides
of
hood
.
Lift
hood
off
carefully
See
Fig
.
8
.

Fig
.
8
.



Hood
hinge
bolts
(arrows)
.
Right
side
shown
.

5
.
Installation
is
reverse
of
removal
.

NOTE-

The
hood
was
fitted
and
attached
to
an
unfinished
body
at
the
factory
.
Unfinished
surfaces
exposed
by
this
pro-
cedure
must
betouchedup
wfth
pafnt
.

Hood,
aligning

ENGINE
HOOD

0013149

6013150

Fig
.
9
.



Hood
panel
gaps
should
be
even
(approx
.
5
.5
mm)
at
all
points
(arrows)
.

Hood
release
cable
and
latches,
adjusting

Before
adjusting
hood
latches,
be
sure
the
hood
is
aligned

evenly
to
fenders
and
front
panel
.
The
hood
latch
and
cable

assembly
is
shown
in
Fig
.
10
.

"
Repair
any
paint
damage
and
paint
any
exposed
metal
.

"
Check
hood
alignment
as
described
next
.



1
.
To
adjust
hood
cables
:

When
installing
the
hood,
align
the
hinges
as
close
to
the
original
paintedsurface
as
possible
.
Movement
of
the
hood
on
its'attaching
hardware
may
require
touch-up
paint
.

The
hood
should
be
aligned
so
that
gapson
all
sides
areas

even
as
possible
.
See
Fig
.
9
.

Clearance
Specification

"
Hood
edges
to
adjoining
body

panel
(gap)
........
..
..
..
.....
.5
.5
mm
(0.216
in)

"
Remove
left
and
right
radiator
grilles
.
See
510
Exterior

Trim,
Bumpers
.

"
Remove
electric
auxíliary
cooling
fan
.
See
170
Radia-

tor
and
Cooling
System
.

"
Adjust
cable
section
between
two
hood
latches
so

there
is
no
play
(cables
must
not
be
under
tension
ei-

ther)
.

2
.
Loosen
hood
latches
at
hood
on
left
and
right
sides
.

Loosen
bolts
only
enough
to
allow
movement
of
latch
.

See
Fig
.
11
.

3
.
Lower
(but
do
not
fully
latch)
hood
severa¡
times
so

latches
on
hood
center
themselves
in
lower
locks
.

CA
UTION-

Do
not
let
hood
fockwith
latchbolts
loose
.

4
.
Tighten
hood
latch
bolts
when
alignment
is
correct
.

5
.
Remove
one
screw
fromeach
side,
clean
and
coat
with
Loctite
O
270
or
equivalent,
and
reinstall
.

Center
hood



,
00--&---
cable



Hood
latch
_
I



upperleft

Fig
.
10
.
Hood
locking
components
.
Cable
adjusting
section
shown
at
inset
.

Fig
.
11
.
Hood
latch
mounting
bolts
(arrows)
.
Left
latch
shown
.

Hood
lock



0013160
lower
left

6
.
Test
hood
for
correct
closure
and
opening
.
If
hooddoes

notspring
open,
lengthen
springpins
at
latches
.
See

Fig
.
12
.

FENDERS,
ENGINE
HOOD



410-5

001aio

Fig
.
12
.
To
lengthen
spring
pin,
loosen
locknut
with
wrench
inserted
through
spring,
then
turn
pin
(arrow)
counterclockwise
.

ENGINE
HOOD

BMW
emblem,
removing
and
installing

The
procedure
given
below
applies
to
both
front
and
rear

emblems
.

1
.
Wrap
and
of
a
screwdriver
with
tape
.

CAUTION-

Protect
hood
paint
by
coveringarea
aroundem-

blem
with
tape
.

2
.
Carefully
pryout
emblem
.
See
Fig
.
15
.

UVI1'¿.

Fig
.
15
.
BMW
emblem
being
removed
.
Pry
up
emblem
carefully
on
ei-

ther
side
(arrows)
.
Note
tape
on
screwdriver
tips
.

3
.
Installation
is
reverse
of
removal
.

"
Replace
plastic
inserts
in
body
if
damaged
.

"
If
emblem
fits
loosely
intoinserts,
use
a
small
amount

of
bodymoldingtape
or
adhesiva
on
rear
of
emblem

before
installing
.

Body
side
molding,
replacing

To
remove
body
side
moldings,
carefully
pry
the
moldings

straight
off
.
See
Fig
.
16
.

Installation
is
the
reverse
of
removal
.
Replace
any
clips
or

clip
covering
boots
damaged
during
removal
.

Radiator
grille,
removing
and
installing

1
.
Remove
plastic
front
radiator
shroud
or
air
duct,
as

needed

2
.
Lightly
tap
center
of
grilla
toward
radiator
andremove

from
panel
opening
.
Chrome
ring
pulís
out
from
front
.

See
Fig
.
17
.

3
.
To
replace,
snap
grille
andchrome
piece
together
.

Push
assembly
into
front
panel,
pressing
at
top
and

bottom
until
it
snaps
into
place
.

EXTERIOR
TRIM,
BUMPERS



510-7

Fig
.
16
.
Body
sida
molding
retainingclips
(arrows)
.

-



0013048

Fig
.
17
.
Radiator
grille
being
tapped
inward
.
Right
side
front
panel
top

retaining
screw
is
shown
at
A
.

Front
panel,
removing
and
installing

The
front
panel
is
shown
in
Fig
.
18
.

1
.
Remove
front
bumper
as
described
earlier
.

2
.
Remove
headlights
.
See
630
Exterior
Lighting
.

3
.
Remove
radiator
grille
as
described
earlier
.

4
.
With
engine
hood
open,
remove
front
panel
retaining

screws
at
left
and
right
sides
of
radiator
.
See
Fig
.
19
.

EXTERIOR
TRIM

600
Electrical
System-General

GENERAL
.
...........
.
.
.
.
.
.
.
.
.
...
.
...
600-1

Voltage
and
Polarity
........
.
.
.
.
.
.
.
.....
600-1

Ming,
Fuses
and
Relays
............
.
.
.
.
600-1

Electrical
System
Safety
Precautions
...
.
.
.
.
600-1

Electrical
Test
Equipment
.....
.
.
.
....
.
.
.
.
600-2

WIRING
DIAGRAMS
..
.
.
.
.
.
.
.
.
.
........
600-2

Ming
Codes
and
Abbreviations
..
.
...
.
....
600-2

ELECTRICAL
TROUBLESHOOTING
..
.
..
600-3

Voltage
and
Voltage
Drops
..........
.
.
.
.
.
600-4

GENERAL



Electrical
System
Safety
Precautions

A
brief
description
of
the
principal
parts
of
the
electrical
sys-
tem
is
presented
here
.
Also
covered
here
are
basic
electrical
system
troubleshooting
tips
.

Voltage
and
Polarity

The
vehicle
electrical
system
is
a
12-volt
direct
current
(DC)
negative-ground
system
.
A
voltage
regulator
controls
system
voltage
at
approximately
the
12-volt
rating
of
the
battery
.
Al¡
circuits
are
grounded
by
direct
or
indirect
connection
to
the

negative
(-)
terminal
of
the
battery
.
A
number
of
ground
con-

nections
throughout
the
car
connect
the
wiring
harness
to

chassis
ground
.
These
circuits
are
completedby
the
battery

cable
or
ground
strap
between
the
body
and
the
battery
nega-

tive
(-)
terminal
.

Wiring,
Fuses
and
Relays

Nearly
all
parts
of
the
wiring
harnessconnect
to
compo-

nents
of
the
electrical
system
with
keyed,
push-on
connectors

that
lock
into
place
.
Notable
exceptions
arethe
heavy
battery

cables
and
the
starter
wiring
.
The
wiring
is
color-coded
for
cir-

cuitidentification
.

With
theexception
of
the
battery
charging
system,
most

electrical
power
is
routed
from
the
ignition
switch
or
the
bat-
tery
through
the
main
fuse/relay
panel,
located
in
¡he
left
rear

comer
of
the
engine
compartment
.
Fuses
are
color
coded
to

indicate
current
capacities
.

The
relays
and
control
units/modules
are
mounted
in
vari-

ous
places
throughout
the
vehicle
.
See610
Electrical
Com-

ponent
Locations
.

ELECTRICAL
SYSTEM-GENERAL
600-1

Voltage,
measuring
.
.
.
................
.
.
600-4

Voltage
drop,
testing
.
.
.....
.
.....
.
......
600-4

Continuity,
checking
..
.
...
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
600-5
Short
Circuits
.
.
.
.
.
.
.
.
.....
.
...
.
.
.
.
.
.
.
.
.
600-5

Short
circuit,
testing
with
ohmmete'r
.
.
.
.
.
.
.
.
.
600-6

Short
circuit,
testing
with
voitmeter
.
.
.
.
.
.
.
.
.
600-6

TABLES
a
.
Terminal
and
Circuit
Numbers
..............
..
.600-3
Please
read
the
following
warnings
and
cautions
before
do-
ing
any
work
on
your
electrical
system
.

WARNING
-

"
The
cars
covered
by
this
manual
are
equipped
with
aSupplemental
Restraint
System
(SRS)
that
automatically
deploys
one
or
more
airbags
.
Each
airbag
unit
houses
an
explosive
powerful
charge
.
Any
work
involving
the
SRS
system
should
only
be
performed
byan
authorized
BMW
dealer
.
Making
repairs
without
the
proper
knowledge
and
special
test
equipment
may
cause
serious
per-
sonal
injury
.
See
721
Airbag
System
(SRS)
.

"
The
ignition
system
of
the
car
operates
at
lethal
voltages
.
People
with
pacemakers
or
weak
hearts
should
not
expose
themselves
to
the
ignition
sys-
tem
.
Extra
caution
mustbe
taken
when
working
on
the
ignition
system
or
when
servicing
theen-
gine
while
it
is
runningor
the
key
is
on
.
See
120
Ignition
System
for
additional
ignition
system
warnings
and
cautions
.

"
Before
operating
the
starter
without
starting
the
engine
(as
when
making
a
compressfon
test),
dis-
able
the
ignition
system
as
described
in
120
Igni-
tion
System
.

"
Keep
hands,
clothing
and
other
objects
clear
of
the
electric
radiator
coollng
fan
when
working
on
a
warm
engine
.
The
fan
may
start
at
any
tíme,
even
when
the
ignition
is
switched
off
.

GENERAL

600-2



ELECTRICAL
SYSTEM-GENERAL

CAUTION
-

"
Always
turn
off
the
engine
and
disconnect
the

negative
()
cable
from
the
batterybefore
remov-

ing
any
electrical
components
.
Disconnecting
the

battery
may
erase
fault
code(s)
stored
in
control

module
memory
.
Check
for
fault
codes
using
spe-
cial
BMW
diagnostic
equipment
.

"
Prior
to
disconnecting
the
battery,
read
the
bat-

tery
disconnection
cautions
given
at
the
front
of

this
manual
onpage
viii
.

"
Connect
and
disconnect
ignition
system
wires,
multiple
connectors,
and
ignition
test
equipment
leads
only
while
the
ignition
is
off
.

"
Do
not
disconnect
the
battery
with
engine
run-

ning
.

"
Do
not
quick-charge
the
battery
(for
boost
start-
ing)
for
longer
than
one
minute,
and
do
not
ex-
ceed
16
.5
volts
at
the
battery
with
the
boosting
cables
attached
.
Wait
at
feast
one
minute
before
boosting
the
battery
a
second
time
.

"
Do
not
usea
test
famp
that
has
a
normal
incan-

descent
bulb
to
test
circuits
contafning
electronic
components
.
The
high
electrical
consumptionof
these
test
lamps
may
damage
the
components
.

"
Do
not
use
an
analog
meter
.
Use
onfy
a
digital
multimeter
.

"
Many
of
the
solid-state
modules
are
static
sensi-
tive
.
Static
discharge
will
permanently
damage
them
.
Always
handle
the
modules
using
proper
static
prevention
equipment
and
techniques
.

"
To
avoid
damaging
harness
connectors
or
relay
panel
sockets,
use
jumper
wires
with
flat-blade
connectors
that
are
the
same
size
as
the
connec-
tor
or
relay
terminals
.

"
Always
switch
a
digital
multimeter
to
the
appropri-
ate
function
and
range
before
making
test
con-
nections
.

"
Do
not
tryto
start
the
engine
of
a
carwhich
has
been
heated
above176°F
(80°C),
(for
example,
in
a
paint
dryingbooth)
.
Allow
it
to
cool
to
normal
temperature
.

"
Disconnect
the
battery
before
dolng
any
electric
welding
on
the
car
.

"
Do
not
wash
the
engine
while
it
is
runnfng,
or
any-
time
the
ignition
is
switched
on
.

WIRING
DIAGRAMS

Electrical
Test
Equipment

Many
of
the
electrical
tests
described
in
this
manual
call
for

measuring
voltage,
currentorresistanceusing
a
digital
multi-

meter
(DMM)
.
Digital
meters
are
preferred
for
precise
mea-

surements
and
for
electronics
work
because
they
are
generally
more
accuratethan
analog
meters
.
The
numerical

display
is
alsoless
likely
to
be
misread,
since
there
is
no
nee-

dle
position
to
be
misinterpreted
by
reading
at
an
angle
.

An
LED
test
light
is
a
safe,
inexpensive
tool
that
can
be
used

to
perform
many
simple
electrical
tests
that
would
otherwise

require
a
digital
multimeter
.
The
LED
indicates
when
voltage

is
present
between
anytwo
test-points
in
a
circuit
.

CA
UTION-

"
Choose
test
equipment
carefully
.
Use
a
digital

multimeter
with
at
leadt
10
megaohm
input
im-

pedance,or
an
LED
test
light
.
An
analog
meter
(swing-need1e)
ora
test
light
with
a
normal
incan-
descent
bulb
may
draw
enough
current
to
dam-
age
sensitive
electronic
components
.

"
An
ohmmeter
must
not
beused
to
measure
resis-
tance
on
solidstate
components
suchas
controlunits
or
time
delay
relays
.

"
Always
disconnect
the
battery
before
making
re-

sístance
(ohm)
measurements
on
the
circuit
.

WIRING
DIAGRAMS

The
wiring
diagrams
shown
in
Electrical
Wiring
Diagrams

have
been
specially
designed
to
enable
quick
and
efficientdi-

agnosis
and
troubleshooting
of
electrical
malfunctions
.

Wiring
Codes
and
Abbreviations

A
lot
of
information
is
included
in
each
wiring
diagram
if
you
know
how
to
read
them
.
Wire
colors
in
the
diagrams
are
ab-

breviated
.
Combined
color
codes
indicate
a
multi-colored
wire
.
For
example
the
code
BLU/RED
indicates
a
Blue
wire

with
a
Red
stripe
.

Many
electrical
components,
connectors,
fuses,
and

ground
locations
are
identified
using
a
unique
number
.
Each

of
there
numbers
corresponds
to
a
particular
part
in
the
circuit
commonly
found
in
Electrical
Wiring
Diagrams
.

600-
4



ELECTRICAL
SYSTEM-GENERAL

Voltage
and
Voltage
Drops

The
wires,
connectors,
and
switches
that
carry
current
are

designed
with
very
low
resistance
so
that
current
flows
with
a

minimum
loss
of
voltage
.
A
voltage
drop
is
caused
by
higher
than
normal
resistance
in
a
circuit
.
This
additional
resistance

actually
decreases
or
stops
the
flow
of
current
.
A
voltage
drop

can
be
noticed
byproblems
ranging
fromdim
headlights
to
sluggish
wipers
.
Some
common
sources
of
voltage
drops
are
corroded
or
dirty
switches,
dirty
or
corroded
connections
or

contacts,
and
loose
or
corroded
ground
wires
and
ground
con-

nections
.

A
voltage
drop
test
is
a
good
test
to
make
if
current
is
flowing
through
the
circuit,
butthe
circuit
is
not
operating
correctly
.
A
voltage
drop
test
will
help
to
pinpoint
a
corroded
ground
strap
or
a
faulty
switch
.
Normally,
there
should
be
less
than
1
volt

drop
across
most
wires
or
closed
switches
.
A
voltage
drop
across
a
connector
or
short
cable
shouldnot
exceed
0
.5
volts
.

Voltage,
measuring

1
.
Connect
digital
multimeternegative
lead
to
a
reliable
ground
point
oncar
.

NOTE-

The
negative
(-)
battery
terminal
is
alwaysa
good
ground
point
.

2
.
Connect
digital
multimeter
positive
lead
to
point
incir-
cuit
you
wish
to
measure
.
See
Fig
.
1
.
If
a
reading
is
ob-
tained,
current
is
flowing
through
circuit
.

NOTE-

The
voltage
reading
shouldnot
deviate
more
than
1
volt
from
the
voltage
at
the
battery
.
If
the
voltage
drop
is
more
than
this,
check
for
acorroded
connector
or
cose
ground
wire
.

ELECTRICAL
TROLIBLESHOOTING

from
Battery

Fig
.
1
.



Digital
multimeterbeing
used
to
test
voltage
.

No
voltage
r_l

-1
Load

LJ

Switch

NOTE-

The
maximum
voltage
drop
in
an
automotive
circuit,
as
recommended
by
the
Society
of
AutomotiveEngineers
(SAE),
is
as
follows
:
0
voltsfor
small
vire
connections
;
0
.1
Volts
for
high
current
connections
;
0
.2
volts
for
high
current
cables
;
and
0
.3volts
for
switch
or
solenoidcon-
tacts
.
On
longer
wires
or
cables,
the
drop
may
be
slight-ly
higher
.
In
any
case,
a
voltage
drop
of
more
than
1.0volt
usually
indicates
a
problem
.

0013238

NOTE-

"
A
voltage
drop
test
is
generally
more
accuratethan
a



Voltage
drop,
testing

simple
resistance
check
because
the
resistances
in-
volvedare
often
too
small
to
measure
with
most
ohm-



Voltage
drop
can
only
be
checked
when
current
is
running
meters
.
For
example,
a
resistance
as
small
as0
.02



through
the
circuit,
suchasby
operating
the
starter
motor
or
ohms
would
results
in
a
3
volt
drop
in
a
typical
150



turning
onthe
headlights
.
A
digital
multimeter
should
beused
amp
starter
circuit
.
(150
amps
x
0
.02
ohms
=3
volts)
.



lo
ensure
accurate
readings
.

"
Keep
in
mind
that
voltage
with
the
key
on
and
voltage
with
the
engine
running
arenotthe
same
.
With
the
ig-



1
.
Connect
digital
multimeter
positive
lead
to
positive
(+)
nition
on
and
the
engine
off
(battery
voltage),
voltage



battery
terminalor
a
positive
power
supply
close
lo
bat
should
be
approximately
12
.6volts
.
With
the
engine



tery
source
.
running
(charging
voltage),
voltage
should
be
approx-
imately
14
.0
volts
.
Measure
voltage
at
the
battery
with



2
.
Connect
digital
multimeter
negativelead
to
other
end
of
the
ignition
on
and
then
with
the
engine
running
to
get



cable
orswitch
being
tested
.
See
Fig
.
2
.
exact
measurements
.

3
.
With
power
on
and
circuit
working,
meter
shows
volt-
age
drop
(difference
between
two
points)
.
This
value
should
not
exceed
1
volt
.