# yet another blower motor thread



## Hyunduzu (Dec 19, 2003)

first off, yes I did search here as well as at sentra & se-r.net...

I found a thread here in which someone asked what I need to know, but it went unanswered so here it is:

settings 1-2-3 worked, but not 4. this seems to be the opposite of the resistor related problem. car idles up so the switch is good. but now it doesn't work at all - still idles higher but no air coming out. :wtf:

checked for power at the blower connector and got ~8V (don't know what setting, didn't try all, but there was power).

obviously this points to the blower itself. is there a way to check the motor? resistance specs? use a jumper wire to hook direct to the battery? any possiblity the resistor has something to do with it?

TIA
:cheers:


----------



## nxchef (Oct 6, 2003)

Hyunduzu said:


> first off, yes I did search here as well as at sentra & se-r.net...
> 
> I found a thread here in which someone asked what I need to know, but it went unanswered so here it is:
> 
> ...


get a new resistor from some store and try it you coulda messed up that part of the resistor and it no longer gives full power.


----------



## BikerFry (Jul 31, 2003)

Correct me if I'm wrong, but isn't the highest setting is at zero resistance. That's why if the resistor dies the last setting still works. I'd bet there's something wrong with the 4th setting on the switch. It's staying open instead of closing and allowing full power through the circuit.


----------



## Hyunduzu (Dec 19, 2003)

thanks for the replies.

can anyone w/factory manual give some specs for checking the switch, resistor, & motor?


----------



## nxchef (Oct 6, 2003)

HEATER SYSTEM
1993 Nissan Sentra
1993 Heater Systems
Pulsar NX & Sentra

DESCRIPTION

HEATER
Heater assembly is contained in a housing beneath instrument
panel. Assembly consists of blower motor, heater housing and core,
heater valve, and control panel.

VENTILATION
Ventilation is a separate function from heating and is
combined with the heating unit to obtain fresh air ventilation when
required. Separate selector lever, push button or position setting on
mode lever permits fresh air to enter passenger compartment. Blower
switch position determines airflow volume.
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article in ACCESSORIES & ELECTRICAL section.
OPERATION

MODE SELECTION
Mode lever or push button controls airflow doors (intake,
blend-air, heat, defrost and ventilation). Lever setting on control
panel determines door positions.
Recirculation/Fresh Door
With door in the open position, outside air flows into heater
system after passing through blower motor fan. With door in closed
position, inside air is recirculated through heater system.
Ventilation Door
Ventilation door (fresh vent door on some models) permits
fresh air to flow from dash panel registers.
Defrost Door
Controls air delivery or defroster outlets when this mode is
selected. This separate door opens when mode door closes off floor and
dash panel outlets to direct air to windshield.
Blend-Air Door
See TEMPERATURE LEVER.

TEMPERATURE LEVER
This lever setting positions blend-air door to direct flow of
air through heater core (hot setting), around heater core (cold
setting) or mixture of both. The lever also controls opening and
closing of heater valve. At any setting except cold, heater valve is
open, allowing engine coolant into heater.

BLOWER SWITCH
Switch controls speed of blower motor through resistor
assembly. Either a dial knob or control lever may be used to select
blower speeds.

ADJUSTMENTS
AIR INTAKE DOOR CABLE
Place air intake door and control lever to recirculation
setting. Remove cable retaining clip. Ensure intake door and cable are
in full recirculation position. See Fig. 1. Attach control cable
retaining clip, and check air intake door operation.

FRESH VENT DOOR
Pull fresh ventilation lever down to off position. Pull cable
to remove any slack. Attach control cable and retaining clip. Check
air intake door operation.

MODE INTAKE DOOR
1) Before installing intake door motor, ensure wiring harness
connector of intake door motor is connected. Turn ignition on. Depress
recirculation button or move mode lever to recirculation setting.
2) Install intake door motor and lever (if removed). See
Fig. 2. Set intake door rod in recirculation position and fasten door
rod to holder on intake door lever. Ensure intake door operates
properly when recirculation button is pressed on and off or mode lever
is moved to and from recirculation setting.

MODE (AIR) CONTROL CABLE
Place mode selector lever to defrost position. Disconnect
control cable and push side link toward cable until it stops. See
Fig. 3. Airflow door is now in full defrost position. Connect cable.
Pull cable in opposite direction to remove slack, and secure cable
using retaining clip.

MODE DOOR
1) Rotate side link clockwise and hold mode door in vent
position. See Fig. 4. Install mode door motor on heater assembly, and
connect wiring harness connector. Turn ignition on. Depress vent
button or move mode lever to vent setting.
2) Install rod of mode door motor to side link rod holder.
Depress defrost button (or move mode lever to defrost setting), and
ensure side link operates at fully open position. Depress vent button
(or move mode lever to vent setting), and ensure side link operates at
fully open position.


TEMPERATURE CONTROL CABLE & HEATER VALVE CONTROL ROD
NOTE: Before adjusting heater valve control rod, disconnect
temperature control cable from blend-air door. After
adjusting control rod, install temperature control cable and
adjust it as necessary.
1) Place temperature lever to maximum hot setting. Disconnect
temperature control cable from blend-air door lever.
2) Pull heater valve control rod in direction of arrow to
obtain .08"(2.0 mm) clearance between ends of rod and link lever. See
Fig. 5. Connect rod to door lever. Check operation of air mix door.
3) Push temperature control cable and air mix door lever in
direction of arrow. See Fig. 6. Install retaining clip.

TROUBLE SHOOTING

NO HOT AIR
Check for malfunctioning engine coolant thermostat, plugged
heater core, and low coolant level. Check for malfunctioning blend-air
door and heater valve not opening.

NO AIRFLOW TO FLOOR
Check for low blower motor speed, poor electrical connection
or blower switch and faulty resistor. Check for malfunctioning floor
air door or floor air door actuator.

LOW AIRFLOW TO DEFROSTER
Check for malfunctioning floor/defroster door, faulty door
seal and plugged defroster nozzle. Check for leaking duct-to-nozzle
connection. Check for defroster door actuator malfunction.

HOT AIR AT ALL TIMES
Check for heater valve not closing. Check for malfunctioning
mode door and faulty mode door seal.

NO BLOWER MOTOR OPERATION
Check for blown fuse and melted fusible link. Check for
disconnected electrical lead to motor. Check for defective fan switch
and defective blower motor. Check for defective resistor and defective
blower relay (if equipped).

CONTROL LEVER DIFFICULT TO OPERATE
Check for inner wire rubbing on outer case end. Check for
kinked or bent cable. Check for sticking doors or lever.

OUTSIDE AIR ENTERING WHEN FAN IS OFF
Check air intake door adjustment. Check control cable
adjustment. Check for air intake door actuator malfunction.

BLOWER MOTOR/FAN NOISE
Check for loose bolt and foreign objects in blower fan. Check
for broken blower fan blades.

TESTING
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article in ACCESSORIES & ELECTRICAL section.

BLOWER SPEED CONTROL SWITCH
Disconnect blower switch connector. Check for continuity at
specified terminals. See TESTING BLOWER SPEED CONTROL SWITCH table.
If continuity is not as specified, replace heater control assembly.
TESTING BLOWER SPEED CONTROL SWITCH TABLE


----------



## nxchef (Oct 6, 2003)

TESTING BLOWER SPEED CONTROL SWITCH TABLE
Switch Position Continuity Between Terminals
OFF .............................. No Continuity
1 .................................. 12, 23 & 27
2 .................................. 12, 23 & 26
3 .................................. 12, 23 & 25
4 .................................. 12, 23 & 24

heater control assembly connector
---------------------
| 12 24 25 26 27 23 |
---------------------

REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article in ACCESSORIES & ELECTRICAL section.

BLOWER MOTOR
Removal & Installation
Disconnect battery. Disconnect blower wiring harness
connector. Disconnect control cable from air intake door. Remove lower
dash trim panel (if necessary). Remove blower motor screws. Remove
blower motor. To install, reverse removal procedure.

HEATER ASSEMBLY
Removal & Installation
See EVAPORATOR & HEATER CORE ASSEMBLY under REMOVAL &
INSTALLATION in MANUAL A/C-HEAT SYSTEM article.

HEATER CONTROL ASSEMBLY
NOTE: Altima removal and installation procedures are not available
from manufacturer.
Removal & Installation
1) Remove heater control bezel (if necessary). Remove radio.
Remove control unit screws. Remove control cables by unfastening
clamps at door levers. Remove heater control assembly bolts.
2) Disconnect wiring harness connector, and remove heater
control assembly. To install, reverse removal procedure. Adjust
cables, and check system operation.


----------



## Hyunduzu (Dec 19, 2003)

you're the man. many thanks! :thumbup: :cheers:


----------

