1996 HONDA CIVIC 1 page

lllustrated Index
'96 - 98 Models
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS
section {24) before performing repairs or service.
BLOWER UNITReplacement, page 21-37Overhaul, page 21-38
HEATER UNITBeplacement, page 21-39Overhaul, page 21-41BLOWERRESISTOBTest,
CONTROL MOTORTest, page 21-48Replacement, page 21'48
a/c swtTcH{wirh A/c)
MOO€MOTORTest, page 21 47Replacement, page 21'47
AIR MIX CONTROL CABLEAdjustment, page 2'1-44Replacement, page 21'43
HEATER FANswtTcHTest, page 2l'49
MODEHEATER CONTBOLPANELswrTcHEsTest, page 21 50Rgplacement, page 2'l-42Overhaul, page 21-43
TEMPERATURE CONTROLLEVERAdiustment, page 21 44
Detroster-aqtivated A/C System
Turning the defroster on activates the A,/C and sets the air flow mode to FRESH. lt is possible to turn the A,/C off or to
change the air flow to RECIRCULATE by pressing the A/C bunon or the FRESH/RECIRCULATE button.
21-2

'99 - 00 Models
SRS components are located in this area, Review the SRS component locations, precautions, and procedures in the SRS
section (24) betore perfoming repairs or service.
HEATER UNITReplacement, page 21'39
Overhaul, page 21-41
BLOWEB UNITReplacement, page 21-37Overhaul, page 21 38
HEATER FANswtTcH
RECIRCULATIONCONTROL MOTORTest, page 21-48Beplacement, page 21-48
AIR MIX CONTROL MOTOBTest, page 21-46Replacement, page 21 46
BLOWERTest, page 21-49
POWER TRANSISTORTest, page 21 50
HIGH RELAY
MODE CONTROLDIALHEATER VALVE CABLEAdjustment, page 21 45TEMPERATURE CONTROLDIALAdjustment, page 21-45
REAR WINDOWDEFOGGERswtrcHSee section 23MODEMOTORTest, page 21 47Replacement, page 2 l-47A/C SWTTCH
lwith A/cl
CONTROL SWITCH
21-3

Troubleshooting -'96 - 98 Models
Symptom Chart
NOTE;
. Check the engine coolant level. and allow the engine to warm up before troubleshooting.
. Any abnormality must be corrected before continuing the test.
. Because of the precise measurements needed. use a multimeter when testing.
o Before performing any troubleshooting procedures check:- Fuses No. 41 11.5 Al, No. 55 (40 A) in the under-hood fuse/relay box. and No. 17 (7.5 A) in the under-dash fuse/relay
box- Grounds No. G401, G402- Cleanliness and tightness of all connectors
SymptomRomedy
Hot air flow is low.Blower motor runs. but one or more
speeds are inoperative.
Perform the procedures in the flowchart (see page 21-8).
Blower runs properly.Check for the following:. Clogged heater duct. Clogged heater outlet. Incorrect door position
No hot air flow.Blower motor does not run at all,Perform the procedures in the flowchart (see page 21-10).
Blower motor runs.Check for the following:. Clogged heater duct. Clogged blower outlet. Clogged heater valve. Faultv air mix door. Heater valve cable adjustment (see page 21-44). Air mix control cable adiustment (see page 2'l-441. Faulty cooling system thermostat (see section 10). Clogged evaporator (with air conditioning). Frozen evaporator {with air conditioning)
Mode control motor does not run, or one or more modes
are inooerative.
Perform the procedures in the flowchart (see page 21-13).
Recirculation control door does not chanqe between
FRESH and RECIRCULATE.
Perform the procedu.es in the flowchan (see page 21-16).
Both heater and A,/C do not work.Perform the procedures in the flowchart (see page 21-18),
21-6

Troubleshooting -'96 - 98 Models
Blower Motor Speed
HEATER FAN SWITCH 6P CONNECTOR
Wire side of female terminals
21-a
Blower motor runs. but one orrnore speeds are inoperative,
Chsck for a short or an open inthe wire{s}:Turn the ignition switch ON {ll),and the heater fan switch OFF.
Does the blower motor run?
Check for a shon in th6 wirels):1. Turn the ignition switch OFF.2. Disconnect the blower motor2P connector,3. Remove the center dashboardlower cover (see section 20),and disconnect the heater lanswitch 6P connector,4. Disconnect the blower resistor 4P connector,5. Check for continuity betweenthe No. 2,3, 4 and 5lerminalsof the heater fan switch 6Pconnector and body ground
individually.
ls there continuity?Reolace the heater fan switch,
Repair short in the wire(s)beiween the blower resistor, theheater tan switch and the blowermotor,
To page 21 9

Troubleshooting -'96 - 98 Models
Blower Motor
BLOWER MOTOR 2P CONNECTOR
Wi.e side of fernale terminals
f=
l1l
r,l
ruumifalulau**'
I
Fl gr-urwnr
l1|_-_-l
t4 ,t
I
glower motor does not run at all.
Check the No.55 (40A)luse in theunder hood fuse/relay box, andthe No. 17 (7.5 A) luse in theundeFdash luse/relay box.
Repl.ce th. fuse{rl, .nd rochack.
Check the blower motor:1. Connect the No. 2 terminal ofthe blower motor 2P connoctor to body ground with a
lumper wrre.2. Turn the ignition switch ON (ll).
Does the blower motor run?
Chock for an opsn in the wire:1. Disconnect the ,umper wireand the blower motor 2P con-nector,2. Measure the voltage betweenthe No. 1 terminal and bodyground.
ls there battery voltage?
Ch6ck tha blower motor relay:1. Turn the ignition switch OFF.2. Remove the blower motorrelay from the under-hoodfuse/relay box, and test it (see
page 21-49).
Replace tha blower moior reley.
To page 21-11
fo page21'12
21-10

From page 2l 10
Check for an open in the wire:
1. Turn the ignition switch OFF,and disconnect the iLrmPer
2. Remove the center dashboardlower cover (see section 20),
and disconnect the heater fanswitch 6P connector.3. Turn the ignition switch ON (ll).
4. Measure the voltage between
the No. 3 terminal and bodygrou nd.
Repair op.n in th6 wiro betw€enthe blower motor and tho heaterfan switch.
Check for an open in the wire:
1. Turn the ignition switch OFF.2. Check for continuity between
the No. 1 terminal of the heatertan switch 6P connector and
body ground.
Reolaco tho heater fan iwitch
Check tor an op€n in the wire
betw.en the heater tan switchand body ground. ll th€ wilo b OK,
check tor poor ground at G401 and
G102.
HEATER FAN SWITCH 5P CONNECTOR
Wire side oI female terminals
(cont'd)
21-11

Troubleshooting -'96 - 98 Models
From page 21-10
Check the under-hood fuse/relayDOX:N/leasure the voltage between theNo. 3 terminal of the blowermotor relay 4P socket and bodyground,
ls there baftery voltage?
Check lor an open in th€ wire:1. Turn the ignition switch ON (ll).
2. Measure the voltage betweenthe No. 4 terminal of the blow-er motor relay 4P socket andbody ground.
Repair open in tho wire betweenthe No. 17 fuss and tho blowelmotor rclay,
Check for en opon in the wire:1. Turn the ignition switch OFF.2. Check for continuity betweenthe No. 2 terminal of the blow-er motor relay 4P socket andbody ground.
Check foi an open in the wirebetwe€n the blower motor relavand body glound. lf the wiro isOK, check fo. poor ground atG{01 and G4O2.
ls there continuity?
Repair open in the BLU/WHTwire b€tween the blower motorrelav and the blower motor.
Blower Motor (cont'dl
BLOWER MOTOR RELAY 'P SOCKET
1211
tt-l_T
trv)
i
21-12

Mode Control Motor
To page 21-14
MODE CONTROL MOTOR 7P CONNECTOR
'1
I2I57
BLK/YEL
Wire side of female terminals
Mode control motor does not run,
or one of more modes are inoPela-
Check the No. '17 (7.5 A) fuse in
the under-dash fuse/relaY box.
Reolace the fuse, and recheck.
Check lor an open in the wire:
1. Disconnect the mode controlmotor 7P connector.2. Turn the ignition switch ON (ll).
3. Measure the voltage betweenthe No. l terminal and bodyg rou nd.
Repair open in the wire between
the No. 17 tuse and the mode
control motor.ls there batterY voltage?
Check {or an open in the wire:1. Turn the ignition switch OFF.
2. Check for continuity between
the No. 7 terminal of the mode
co nlrol motor 7P connector
and body ground.
Check for an open in the wire
batwe€n the mode contrcl motol
and body ground. lf the wir€ is OK,check for poor gtound at G/U)l and
G402.
ls there continuity?
Test the mode control motor (see
page21-471.Check the mod€ control linkage
and doors:1. Bemove the mode controlmotor (see page 21-47).2. Check the mode control linkageand doors for smooth move
ls the mode control motor OK?
Do the mode control linkageand doors move smoothlY?
Reolace the mode control motor,
I34561
BLK
[]
(cont'd)