1999 NISSAN PRIMERA bulb

VOLTAGE DROP TESTS
Voltage drop tests are often used to find components or circuits which have excessive resistance. A voltage
drop in a circuit is caused by a resistancewhen the circuit is in operation.
Check the wire in the illustration. When measuring resistance with ohmmeter, contact by a single strand of
wire will give reading of 0 ohms. This would indicate a good circuit. When the circuit operates, this single
strand of wire is not able to carry the current. The single strand will have a high resistance to the current.
This will be picked up as a slight voltage drop.
Unwanted resistance can be caused by many situations as follows:
Undersized wiring (single strand example)
Corrosion on switch contacts
Loose wire connections or splices.
If repairs are needed always use wire that is of the same or larger gauge.
Measuring voltage drop Ð Accumulated method
1. Connect the voltmeter across the connector or part of the circuit you want to check. The positive lead
of the voltmeter should be closer to power and the negative lead closer to ground.
2. Operate the circuit.
3. The voltmeter will indicate how many volts are being used to ªpushº current through that part of the cir-
cuit.
Note in the illustration that there is an excessive 4.1 volt drop between the battery and the bulb.
Measuring voltage drop Ð Step by step
The step by step method is most useful for isolating excessive drops in low voltage systems (such as those
in ªComputer Controlled Systemsº).
Circuits in the ªComputer Controlled Systemº operate on very low amperage.
The (Computer Controlled) system operations can be adversely affected by any variation in resistance in
the system. Such resistance variation may be caused by poor connection, improper installation, improper
wire gauge or corrosion.
The step by step voltage drop test can identify a component or wire with too much resistance.
SGI848
Symptom: Dim bulb or no operation
0 (zero) ohm
resistance
between switch
and bulb
GroundBatteryDMM
PowerSwitchLoad
Connection with
high resistance
Ground
HOW TO PERFORM EFFICIENT DIAGNOSIS
FOR AN ELECTRICAL INCIDENT
Circuit Inspection (Cont'd)
GI-32

A
AAC/V - Wiring diagram....EC-QG-276, EC-SR-265
ABS (anti-lock brake system).........................BR-50
A/C control linkage adjustment (manual
A/C) .............................................................HA-82
A/C control operation (auto A/C) ....................HA-19
A/C diagnostic work flow (auto A/C) ..............HA-26
A/C performance chart ...................................HA-35
A/C performance test diagnoses....................HA-33
A/C relay.........................................................HA-78
A/C service data specification ......................HA-118
A/C switch ......................................................HA-78
A/C symptom chart (auto A/C) .......................HA-28
A/C trouble diagnoses (auto A/C) ..................HA-26
Accelerator control system ...............................FE-3
Accelerator position sensor ...................EC-CD-108
Accelerator position switch ....................EC-CD-108
Accelerator wire adjustment .............................FE-4
A/CCUT - Wiring diagram ......................EC-CD-127
Air bag disposal..............................................RS-27
Air bag precautions ...........................................GI-3
Air bleeding for brake system ..........................BR-8
Air cleaner filter replacement ............MA-23, 34, 44
Air conditioner cut
control .....EC-QG-24, EC-SR-26, EC-CD-20, 126
Air flow meter - See Mass air flow
sensor ............................EC-QG-110, EC-SR-120
Air mix. door motor.........................................HA-92
Alternator ..................................................EL-53, 56
Ambient sensor ..............................................HA-86
Antenna .........................................................EL-229
Anti-lock brake system - See ABS .................BR-50
APS - Wiring diagram ............................EC-CD-109
A/T - Wiring diagram - AT - FTS .....................AT-56
A/T - Wiring diagram - AT - MAIN ...................AT-45
A/T - Wiring diagram - AT - PNP/SW..............AT-50
A/T - Wiring diagram - AT - VSS A/T ..............AT-64
A/T diagnosis communication line .........EC-SR-295
A/T fluid temperature sensor...........................AT-54
A/T trouble diagnoses ...............................AT-29, 30
A/T Wiring diagram - AT - ENG SS ................AT-67
A/T Wiring diagram AT - LPSV .......................AT-76
A/T Wiring diagram AT - TCV .........................AT-71
A/T Wiring diagram AT - TPS..........................AT-81
ATDIAG - Wiring diagram ......................EC-SR-296
Audio .............................................................EL-216
AUDIO - Wiring diagram ...............................EL-219
Audio and A/C control removal and
installation - See Instrument panel .............BT-15
Auto air conditioner - Wiring diagram ............HA-42
Automatic amplifier .........................................HA-87
Automatic transaxle number............................GI-44
Automatic transmission fluid
replacement..........................................MA-49, 50
Auxiliary air control (AAC)
valve ..............................EC-QG-274, EC-SR-263BBack door opener - See Back door ............BT-9, 11
Back door trim.................................................BT-30
Back door window ....................................BT-35, 56
Back-up lamp ................................................EL-107
BACK/L - Wiring diagram..............................EL-107
Ball joint front axle ....................................FA-32, 33
Base idle air volume
initialiging ...........................EC-QG-33, EC-SR-46
Basic inspection ....................EC-QG-72, EC-SR-84
Battery .............................................................EL-29
Body alignment ...............................................BT-60
Brake booster .................................................BR-18
Brake control valve (Proportioning
valve)...........................................................BR-11
Brake fluid change ...........................................BR-7
Brake fluid level .............................................MA-51
Brake fluid level and line check .......................BR-7
Brake hydraulic line ..........................................BR-9
Brake inspection ............................................MA-51
Brake lining wear temporary checking ..........MA-51
Brake pedal ....................................................BR-13
Bulb specifications ........................................EL-137
Bumper, front ....................................................BT-5
Bumper, rear .......................................BT-5, 7, 9, 11
BUZZER - Wiring diagram ............................EL-181
C
Camshaft inspection ...............EM-35, 91, 138, 147,
183, 192, 196
Camshaft position sensor
(CMPS) ..........................EC-QG-238, EC-SR-239
Camshaft position sensor (PHASE) ......EC-QG-238
Canister-See EVAP
canister ..............................EC-QG-25, EC-SR-27
CHARGE - Wiring diagram .............................EL-53
Charging system .............................................EL-53
Chassis and body maintenance ....................MA-48
CHIME - Wiring diagram ...............................EL-181
Cigarette lighter.............................................EL-203
Circuit breaker.................................................EL-22
CKPS - Wiring diagram....EC-QG-234, EC-SR-236,
292, EC-CD-115
Clock .............................................................EL-203
Closed throttle position switch ...............EC-SR-271
Clutch cover ....................................................CL-13
Clutch damper ................................................CL-10
Clutch disc ......................................................CL-13
Clutch fluid level.............................................MA-48
Clutch master cylinder ......................................CL-8
Clutch operating cylinder ..................................CL-9
Clutch release mechanism..............................CL-11
CMPS - Wiring diagram ....EC-QG-240, EC-SR-242
Coil spring (rear) .............................................RA-11
Collision diagnosis..........................................RS-57
Combination meter........................................EL-138
ALPHABETICAL INDEX
IDX-2