1998 HONDA CIVIC heater switch

'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

'99 - 00 Models
UNDER,HOOO FUSE/RELAY 8OX
PUSN SWITCH
lHce nvosrar F)- aLu neo(Wirh IVC)
DASH LIGHTS -/1BBTGNTNESS < l- FEoCONTROLLER -!
IGN TION SW TCHUNDEF DASHFUSElRELAY BOX
**,',,* **",@ ",.
@f
u,n,",,
ELUAVHT
I
YBLUi BtK
BLOWERMOTOR
ELOWERMOTORHIGHRELAY
PNK/BLK
FED''WHT
RED,YEL
GRY
BRN
YEL
YEL/FEO
6RNiYEL
8LU/!VHT
YEL/BLU
BRNfiHT
GFNM/HT
GRNi FED
O :8P CONNECTOR
! :20P CONNECTOF
E : 12P CONNECToR
BLUi BLK
1
tic
HEATER CONTROL PANEL
VENT
MOOEHEAT CONTFOLMOTOF- M.COMDEF
[[f&H,,4*,",,
BLK

Heater Control Panel Input/Output Signals
HEATER CONTROL PANEL lilP CONNECToR
Wire side of lemale terminals
21-7
Terminal
No.
Wire
colorSignalTerminal
No.
Wire
colorSignal
1YELHEAT/DEFINPUT8YEVREDVENTINPUT
BLfiELINPUT9G RNI/ELHEATIr'ENTINPUT
WHT/BLU+BINPUT'10BLKGROUNDOUTPUT
4YEUBLUDEFINPUT11*BLU/REDA./C THERMOSTATINPUT
5REDDASH LIGHTS
BRIGHTNESS CONTROLLEROUTPUT12GRN/WHTFRESHINPUT
6RE D/8LKCOMBINATION LIGHT
SWITCHINPUT13GRN/REDRECIRCULATEINPUT
1BLUMHTHEATINPUT14GRNHEATER FAN SWITCHOUTPUT

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

ls there approx. 2 - 3 ohms?
Check for an open in the wire(s):1. Reconnect the blower resistor
4P connector,2. Remove the center dashboardlower cover (see section 20),and disconnect the heater fanswitch 6P connector.3. Turn the ignition switch ON (ll).
4. Ground each of these termi-nals individually in the tollow_ing order: No. 4, 2, 5 and 3.
Does the blower motor run atprogressively higher speeds?Reolace the hoater fan switch.
Repair open or cause ol excessiveresistance in the appropriatewire{sl between the blower resis-tor and the heater {an switch.
Check the blower resislor:1. Turn the ignitjon switch OFF.2. Disconnect the blower resistor 4P connector.3, N4easure the resistancebetween the No. 2 and No. 4
terminals of the blower resis-tor,
BLOWER RESISTOR
HEATER FAN SWITCH 6P CONNECTOR
BLU/WHT
2
16
BLUBLU/YEL
BLU/BLK
JUMPERWIRE
Wire side of female terminals
21-9

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
Both heater and A/C do not work.
Check the No. 17 {7.5 A) fuse in theunderdash fuse/relay box, and theNo. 47 (7.5 A) fuse in the underhood fuse/relay box.
R.phce the fuso{s), .nd rccheck.
Chack tor an open in the wi.e:1. Remove the center dashboardlower cover (see section 20),and disconnect the heatercontrol panel 14P connector.2. Torn the ignition switch ON {ll).3. Measure the voltage betweenthe No. 2 terminal of theheater control panel 14P con-nector and body ground.
Rcpair opGn in th€ wiro betwoonthe No. 17 tuse and the hoatclcontrol panel.
ls there baftery voltage?
Check for an opon in the wiro:1. Turn the ignition switch OFF.2. Measure the voitage betweenthe No. 3 terminal of theheater control panel 14P con-nector and body ground.
Rgprii open in th6 wira b€twacnthe No. il7 tui. and the heat.tcont.ol p.nal.
ls there battery voltage?
Check foi an open in the wi.e:Check for continuity between theNo. 10 terminal ot the heater con-trol panel 14P connector andbody ground.
Check lor an opon in tho wireb€{w6on the hoator control oaneland body ground. lI the wirc isOK, check tor poor ground atG401 .nd G4O2.
Check for looae wiaos or ooolconnections at the hoater controlpanol 14P connector. lf the con-nactions dre good. 3ubstitute tknown-9ood heater controlpanel, and rech6ck. It tho symp-tom/indication 9oe3 .wry,replace the original heatel con-trol oanol.
Heater Control Panel
HEATER CONTROL PANEL 1,lP CONNECTOR
Wire side of female terminals
21-18

Troubleshooting -'99 - 00 Models
Self-diagnosis Function
The heater control panel has a self-diagnosis function.
Running the Self-diagnosis Funqtion
Set the mode control dial to the Vent position, and turn the ignition switch ON fll). Within six seconds after turnang the igni_tion switch on. press the recirculation control switch the required number of times depending on the recirculation indicatorlight status:
.lftheindicatorlightisON,presstherecirculationcontrolswitchfivetrmes.
.lftheindicatorlightisOFF,presstherecirculationcontrol switch six rrmes.The recirculation indicator light will come on for two seconds. then blink the Diagnostic Trouble code {DTc} to indicate afaulty component. lf no DTc's are found, the indicator light will not blink after the initial two second liqht.
DTC Indication Pattern (S6e DTC 2l:
Recirculationindicato.light on
Recirculationindicatorlight off2 sec
,/1.5 soct
' 0,3 secWithin six seconds atter theignition switch is turned ON (lll,pross the recirculation controlswitch the required number ottimes depending on the rocircu-lation indicetor light status
0.3 sec
VENT POSITIONMODE CONTROL DIAL
RECIRCULATIONCONTROL SWTCH
DTC Troubleshooting Index
Diagnostic
trouble
code (DTCI
Rgcirculation
indicator lightComponent with problemPossible causeSee page
One blinkAir mix control motorObstructed door, laulty motor21-21
2Two blinksAir mix control motorOpen or short circuit21-23
ln case of multiple problems, the recirculation indicator light will indicate only one DTc with the least number of blinks.
Resetting the Self-diagnosis FunctionTurning the ignition switch OFF will cancel the self-diagnosis function, After completing repair work, run the setf diagnosisfunction again to make sure that there are no other malfunctions.
21-20
@
At
V'