1998 HONDA CIVIC Heater motor

Troubleshooting -'99 - 00 Models
Heater Control Panel Input/Output Signals
HEATER CONTROL PANEL CONNECTORS
8P CONNECTOR2OP CONNECTOR12P CONNECTOR
Wire side of female terminals
8P CONNECTOR (O qn Circuit Diagram)
20P CONNECTOR {D on circuit Diagram}
*: with Ay'c
12P CONNECTOR (tr on Circuit Diagraml
CavityWire colorSignalCavilyWhe colorSignal
BLU/8LKBLOWER FEEDBACKINPUT5REDDASH LIGHTS BRIGHTNESSCONTROLLEROUTPUT
2GRN/lVHTFRESHINPUT6BLKGBOU N DOUTPUT
3GRN/REDRECIRCULATEINPUT7BLU/YELREAR WINDOW DEFOGGERRELAYOUTPUT
4RED/BLKCOMBINATION LIGHT SWITCH(Via No. 30 (7.5 A) fuse)INPUT88LfiELlG2 {Power)INPUT
CavityWire colorSignalCavityWire colorSignal
LTGRN/BLKPOWER TRANSISTOR EASEOUTPUT't1BLU/REDAy'C THERMOSTATINPUT
2BRNMHTMODE CONTROL MOTORGROUNDINPUT12BRNAIR MIX CONTROL MOTORGROU NDINPUT
3RE D/YELAIR MIX HOTOUTPUT13ORNAA/HTBLOWER MOTOR HIGHRELAYINPUT
RED,ryvHIAIR MIX COOLOUTPUT14
5YEUBLUMODE DEFINPUTPN K,/BLKAIR MIX POTENTIALOUTPUT
6YEUREDMODE VENTINPUT16
7GRNI/ELMODE HEAT/r'ENTINPUT11
IBLUAVHTMODE HEATINPUT18
9YELMODE HEAT/DEFINPUT19
10WHT/BLU+B (Power)INPUT20GRYAIR MIX POTENTIAL +5 VOUTPUT
CavityWilecolorSignalCavityWi.e cololSignal
lSWITCH LED COMMONOUTPUT1SWITCH LIGHTS +OUTPUT
2ISWITCH LIGHTS -INPUT
39SWITCH COMMONINPUT
4RECIRCULATION CONTROLSWITCH LEDINPUT10A,/C SWITCHOUTPUT
5A./C SWITCH LEDINPUT11RECIRCULATION CONTROLSWITCHOUTPUT
6REAR WINDOW DEFOGGERSWITCH LEDINPUT12REAR WINDOW DEFOGGEBSWITCHOUTPUT
21-36

Blower Unit
Replacement
NOTE: The blower motor, recirculation control motor
and blower resistor can bs replacsd without rsmoving
th€ blower unit (see neld Page).
1. Move the temperature control to "HOT."
'96-98: Slide the temperature control lever.'99-00: Turn the ignition switch ON (ll), then turn
the temperature contol knob. Turn the ignition
switch off,
Remove the glovs box (ses ssction 20),
R€move ths s6lf-tapping screw and ths passsng6r's
dashboard low€r cover. Removo the bolt, the nut
and the kn€e bolst€r, then remove the fiv€ bolts and
the glove box trame,
Without Air Condhioning
4-a. Remove the wiro harness from the h68t€r duct, then
remove the two self-tapping scrsws and the heatsr
duct.
KNEE
GLOVE BOX FRAME
HEATER DUCT
21-37
Wrth Air Conditioning
4-b. Removo th6 ev8porator (sss pago 22-28).
6x1.0m|n9.8 N'm
6x1.0mm9.8 N'm lt'o tgf'm, t.2 lb{'ttl
Disconnoct the connectors trom th€ blower motor,
blowor r6sistor {'96 - 98 models), power transiator
('99 - 0O modsls), blowor motor high telay ('99 - 00
models) and recirculation control motor.
R€mov€ ths wiro harnoss clip from tho recirculation
control motor, and release the wir6 harnsss from ths
clamo on the blowor unit. Remove the two mount-
ing bolts, tho mounting nut and ths blowor unit'
9.8 .m 11.0 tgfm,1.2 tblfrl
lnstall in ths reverso order of removal. Mako surs
that thsre is no air leaka96.
6x1.0mm9,t N'm 11.0lgi.m,7.2 tbf.fil

Heater Unit
Replacement (cont'dl
6.
7.
8.
9.
Remove the dashboard (see section 20).
Remove the heater duct (see page 21-37) or evapo-
rator (see page 22-28).
Disconnect the connectors from the mode control
motor and air mix control motor ('99 - 00 models),
then remove the wire harness clips and wire har-
ness from the heater unit. Remove the clip from the
heater duct, then remove the two mounting nuts
and the heater unit.
6x1.0mm9.8 N.m 11.0 kgl.m,7.2 lbf.ftl
HEATER UNIT
lnstall in the reverse order of removal. Make note of
the following items.
Apply sealant to the grommets.
Do not interchange the inlet and outlet heater
hoses. Make sure that the clamps are secure.
Refill the cooling system with engine coolant
(see section 10).
Connect all cables, and make sure they are prop-
erly adjusted (see page 21-44 (96 - 98 models)
or page 21-45 ('99 - 00 models)).
Make sure that there is no air leakage.
21-40

RelaysHeater Fan Switch
Test
There should be continuity between the No 1 and No. 3
terminals when power and ground are connected to the
No.2 and No. 4 terminals, and there should be no conta-
nuity when power is disconnected.
Blower motor relaY
. Blower motor high relay ('99 00 models)
,I It;€'Y )
Test -'96 - 98 Models
Check for continuity between the terminals according to
the table below.
lerminal
Position14253
OFF
1IrJ
2o-o
3o-a
4c)-{
21-49

Circuit Diagram
UNDER DASHFUSE/RELAY 8OX
N0.17 (7.54)
'96 - 98 Models
UNDER.HOOD FUSEi BELAY BOX
WHT/SLU BLKYEL
BLK
+
G751
3
'o
I8LK
I
G40lG402
GNITON SWITCH
N0.41 (8rA) N0.42 (40A)
COMPBESSORCLUTCHBELAY
BLUMHT
,l
(E) i,T'
BLUi BED
A/c ITHERMOSTAI BLU/REO
CONDENSEFFAN MOTOR
*F,.X,
FAN rl
BLK
{
G401G402
HEATERswrlcH
32
22-6

Gonnector ldentification and Wire Harness Routing
Heater Sub-harness A: '96 - 98 models
Connector or
Terminal
Number ot
CavitiesLocationConneqts toNotes
c7 21
c722
c723
c724
c727
7
20
2
Under left side of dash
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Main wire harness (C440)
Mode control motor
Heater sub-harness B 1C741)Ay'C thermostat
Blower motor
Blower resister
Recirculation control motor
Heater Sub-harness B: '96 - 98 mod€ls
HEATER SUB.HARNESS A
Connoctor 01
Terminal
Number of
CavitiesLocationConngcts loNotes
c7 41
c142
c7 43
20
14
Behind glove box
Behind middle of dash
Behind middle of dash
Heater sub-harness A (C723)
Heater fan switch
Heater control panel
23-58
HEATER SUB-HARNESS B

'
Heater Sub-harness A: '99 - 00 models
Connector or
Terminal
Number of
CavitiesLocationConnects toNotes
c721
c722
c723
c724
c725
c726
c727
c728
c729
c730
7
24
3
2
4
1
5
4
Under left side of dash
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Behind glove box
Main wire harness (C440)
Mode control motor
Heater sub-harness B (C741)
lilc thermostat
Blower motor
Power transistor
Recircuiation control motor
Heater sub-harness B (C744)
Air mix control motor
Blower motor high relaY
Heater Sub-harness B: '99 - 00 models
HEATER SUB.HARNESS A
Connector or
Terminal
Number of
CavitiesLocationConnects toNotes
c7 41
c'742
c143
c744
20
8
20
1
Behind glove box
Behind middie of dash
Behind middle of dash
Behind glove box
Heater sub-harness A (C723)
Heater control Panel
Heater control Panel
Heater sub-harness A (C728)

Fuse
NumberAmpsPageFuse Name
(RR WIPER
RR WASHER)
i R HiL HIGH BEAM | 10
L H/L HIGH BEAM
| (PAIV RR-L)
i (P/vv RR-R)
(rGN CO|L)
10I (P,^/V AS)
Component or Circuit Protected
Not used
Not used
Rear wiper, Security system (option)
(Vehicles pre-wired for accessory security system)
'10r 1n-2
I
| 1 10-12i Right headlight, DRL control unit (Canada)
Lett headlight, DRL control unit (Canada)
I ro-rsSecurity system (option)
| 120-2 | Left rear window motor
Right rear window motor
lgnition coil ('98-'00 models except GX)
| 120-1 | Front passenger's window motor
i (PiW DH)| 20 1 12O I Driver's window motor
TURN LIGHTSHazard warning switch
FUEL PUMP
(SRS UNIT)
PGM-FI main relav, SRS unit
(cRUrsE CoNTROL)
/KtrVt trSS\
Stereo radio tuner ('96-'98 USA: LX, EX, and HX),
Cruise control main switch, Keyless door lock
control unit ('99-'00 models with keyless entry)
15ALTERNATOR
SP SENSOR
l-a10-4I ELD unit, Gauge assembly, TCM (96-'98 CW, PGM-FI
16I RR DEF RELAY7.510-8I Rear window defogger ('96-'98 models), ABS control
I unit. Power mirror switch ('99-'00 models except GX)
i-HEATER r/C
I RELAY
Power mirrors ('96-98 models and all GX models),
Air delivery, Blower controls, AilC compressor
controls, Fans
I (RUNNING LIGHT
I RELAY)
1 7.5 1
tl
I DRL control unit (Canada)
i BACK-UP LTGHTSi Back-up lights
(RUNNING LIGHT)DRL control unit (Canada)
I R H/L LOW BEAM'10 l11o-12Right headlight
I L H/L LOW BEAM | 101110-12 | Left headlight
(cont'd)
(SRS)SRS unit
6-1