1998 HONDA CIVIC Fan switch

Power Distribution Schematics
Power Distribution schematics show how power is supplied from the positive battery terminal to
various circuits in the car. Refer to the Power Distribution section to get a more detailed picture
of how power is supplied to the circuit you're working on.
From Battery to lgnition Switch, Fuses, and Relays
Individual circuit schematics begin with a fuse. The first half of Power Distribution, however,
shows the wiring "upstream" between the battery and the fuses.
CYLINDERBLOCK
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i BATTERY
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ruse so I ruse as I ruse ga | ' ,s. ,a I =u. - srl ruse aai ruse qr I ruse so I ruse sr i ruse iapowEF csw FUsE Bc, \F,.n .;,cren ooon \coounc cor,r. \sun noor powrnw'NDowf50a {* .i1-;.*"1liT""fi3f* f5# fffi'*"f'* fS?'*
- - -L - - -. ... Ji - -.J.- - - -e- - -l. - - -La - J- - - I - - -
"";%,, Y rtr,' .9 l' -%,t",,vtEw47 I ! See Power Dastribution,w - vH-,alr. lt - pages 10,10and 10-11.
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It-STARTER | !Pase 21 ! t FUSE 31I "rn*i
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FUSE /I4 ' FUSE 47 ' FUSE 5{' ' FUSE 51' FUSE 52
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OOOB \COOLING CON. \SUN BOOF FOWER
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See Power Dastribution,pages 10'10 and 10-11.
T101
34
ALK
4
GAN
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FUSE 8DF POWEF SEAT204
FUSE 6ECU204
FUSE 5A/C CLUICH(FN HEATEDSEAD204
C901 C921 {NotPHoro zz OPTION Used)v/EW22 CONNECTOBSee Power Distnbution, page 10-2.
1
FUSE 4
FADIO104
c901
vlEw22
FUSE 12(BUltNrrGLIGHT)
FUSE 19R/C MIRROF
YEL
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i-f,r-- 't PowERI uon- I Wlt{DOWi racrs i RELAY. t P^da 1tL-J P;dr1ii-
FUSE 3CONOENSEF FAN RELAYCOOLING FAN RELAY
To Fuses 17, 18, 21,and 24, for details,see Power Windowspage 120.a
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ALTER-NATORPage 22
f102
c330
See Power Distribution, pages 10-4 and 10-5.

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
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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

Fuse
NumberFuse NameAmpsPage
BATTERY
Component or Circult Protected
Power distribution
lgnition switch
INTERIOR LIGHT | 7.5 | 10-10 | DLC, Ceiling light, Trunk light
FI E/M15 i(20 GX) i
i PGM-FI main relay, Fuel injection relay (GX)
Not used
POWER WINDOW| 10-10 | Power window relay
BACK UPStereo radio iuner ('9G'98 mod€ls), Audio unit ('99100
models), Heater control panel, PCM/ECM, TCM (9e'98
cvr)
HEADLIGHT
REAR DEFROSTER I
DOOR LOCK UNIT,
ROOF
i 10-12i Headlights
Not used
Rear window defogger relay
Power door lock control unit (all except '99-'00 models
with keyless), Keyless door lock control unit ('99-'00
models with keyless), Moonroof
i HORN, SrOP Lri 10-13i Horn relay, Brake switch
HAZARDHazard warning switch
OPTIONI 10-13I Security system (option)
i HEATER MOTOR Ii 10-1 i Blower motor relay
(CONDENSER FAN)
COOLING FANl1o-1
Condenser Jan relay, A'lC compressor clutch relay
Radiator tan relay
&5

Ground-to-Components I ndex
f.,lONOTE: All ground wires are BLK unless otherwise noted.
GroundPageComponents or Circuit Grounded
Battery (BLKYEL)
Steering pump bracket
t+-rg ITransmission housing
l
G101
(-1)
G101
(-2)
14-2
and
14-3
ano
14-1
Powertrain or engine control module (PG1 and pG2 are BLK: LG1 and LG2 are
BRN/BLK), EGR control solenoid valve (CW, EGR valve and lift sensor (Dt6yS enginewith M,/T), Engine coolant temperature switch, pGM-Fl main relay, power steeringpressure switch (USA), Primary HO2S (D16Y5 engine with l\/,/T), Vehicle speed sensor,VTEC pressure switch (D16Y5/D16Y8 engines), CKF sensor (BRN/BLK), Transmission
control module (CYf) (Pc1 is BLK: LG1 is BRN/BLK)
Shielding betvveen the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor. Primary and secondary heated oxygen sensors.
Knock sensor (CWDl6YB engine), Mainshaft speed sensor (AiT except CVT),
I Countershaft speed sensor (A/T except CVf)
Shielding between the TCM and these components (CVT) (all have BRN/BLK wires):
Drive pulley speed sensor, Driven pulley speed sensor, Secondary gear shaft
speed sensor
Powertrain or engine control module (PG1 and pG2 are BLK; LG1 and LGz are
BRN/BLK), EGR control solenoid valve (D16Y5 engine), EGR valve (Dt685), Engine
coolant temperature switch, Fuel pressure regulator shut-off solenoid valve (D1685),
PGM-FI main relay, Power steering pressure switch (USA), Vehicle speed sensor, VTECpressure switch (All except D16Y7 engine), CKF sensor (A

except 81642) (BRN/BLK)
Shielding between the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor, Primary and secondary heated oxygen sensors,
Knock sensor (All except D16Y7 engine), i/ainshaft speed sensor (Arf except CW),
Countershaft speed sensor (A,/T except CVf), Drive pulley speed sensor (CW), Drivenpulley speed sensor (CVT), Secondary gear shaft speed sensor (CVf)
I Badiator fan motor, Right front parking/turn signat tight, Right headtight
G20214-4I Cruise control actuator, Left front parking/turn signal lights, Left headlight, Rear window
I washer motor, Windshield washer motor, Washer fluid level switch (,99-'00 Canada)
G401| +-o
and
14-7
Accessory power socket, Brake fluid level switch, Clutch interlock switch (M/T), Clutchswitch (lillT with cruise/D16Y5 engine with MfD, Combination wiper switch (Z wires),
Cruise control main switch, Cruise control unit, Dash lights brightness controller, Data
link connector, Daytime running lights control unit (Canada), Gauge assembly, Horn('96-'97 models), Integrated control unit, Interlock control unit (ArI), Keyless door lock
control unit ('99-'00 models with keyless), Moonroof close and open relays, Moonroof
switch, Park pin switch (A/r), Power window relay, Rear window defogger relay, Rear
window defogger switch ('96-'98 models), Steering lock, Stereo radio tuner (,96-,98
USA: LX, EX, and HX), Turn signal/hazard relay, Windshield wiper motor.....plus
everything grounded through G402
6-6

Ground Distributiofl (cont'd)
- G201 andG202
NOTE: Wires shown wrthout color codes are black.
RIGHTHEAD.LIGHTPage110-12
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110-9
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LEFT FRONTPARKING/TURNSIGNALLIGHTPages 110-2,1 10-7, and110-9
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WIND.SHIELDWASHERMOTORPage 91PHOTA 3
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REARwtNDowWASHERMOTORPage 92
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c205
RIGHT FRONTPARKING/TURNStcNAL RADIATORLIGHT FANPaoes 110-2, MOTOR11d-7, and Page 63
'99-'00
.- Canada -l
i wnsxen i cnurse, FLUID ; CONTROL' LEVEL . ACTUATOR' SWITCH I paoe 34-2; Page 80-3 i eu6ro re'f-1 ' f-1
2Y2
c211
14-4
I'G201'Lv G2o2

Blower Controls
'96-'98 Models
@
UNDER.HOODFUSE/RELAYBOX
UNDER.DASHFUSE/RELAYBOXPHOTO 5A
BLOWEFnoToRBELAYPEOfO I
HEATER FANSWITCH
6 calrSeeL/cCompressorControls
(
See GroundDbtribution,oaqg 14-5.
See GrorDbtributipage 14.
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ar<
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- c402
BLU/YEL1l
BLU/
1BLK
BLK
BLK
60

- How the Circuit Works
Battery voltage is supplied through tuse 56 to the
A,/C compressor clutch r€lay contacts at all times.
With the ignition switch in ON (ll), vollage is applied
to the coil of the A,/C compressor clutch relay
through fuse 17. When you push the A,/C switch
ON, and the heater fan switch is in position | , 2, 3,
or 4, a "ground" input is provided to the engine
control module (ECM) or powertrain control module
(PCM) through the l'lC thermostat and the l'lC
pressure switch.
The A,/C compressor clutch relay is grounded by the
engine control module (ECM) or powertrain control
module (PCM). When energized, the A'lC
compressor clutch relay allows battery voltage to
turn on the A,/C comDressor clutch.
The A,/C ON indicator light comes on when the A,/C
system is requested.
A,/C Thermostat
The A'lC thermostat is located on the evaoorator
housing. The A,/C thermostat turns off the A,/C
compressor clutch if the temperature at the
evaporator goes below 3'C (37'F). This prevents
condensation from freezing on the evaporator fins
and blocking the air delivery into the passenger
compartment. The blower motor will keep running
when the sensor turns off the comDressor.
A,/C Pressure Switch
The fuC oressure switch is located in the condenser
outlet line where refrigerant is in a high
temperature/high pressure liquid state. The switch
will sense abnormally high or low pressure, and
open the circuit. This removes ground, and the
compressor will stop running.
Thermal Protectot
The thermal protector, located on the A,/C
compressor, opens and turns the compressor off if it
senses high temperature. Once the compressor
cools, the switch will close and the compressor will
begin running again.
Refer to the Service Manual (Section 22,
Air Conditioning) for specific tests or
troubleshooting procedures.
62-3

Fans (cont'd)
- '99-'00 Models
Switch"common
a,/cTHERMOSTATOff below3'C (37" F).
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iTm,il-- l5;i;T iln"lgg1
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I I .-.. Sse Power II ',-.', Sse Power I S€€ Pow€r
?+ 3s;iT:3:' ?'4 3ff:?f?l:
OEE I Dbfibution,
I pacp 10.9.
HEATERCONTROLPANEL
vlEw 76
A6
BLK
;+
::--
{***,Pase*11
ItI
rfa
r,/cswitchinputL-----
HEATERPUSHswtTcHEs
A/CSwlbh
See AirDslivery,n6arWindowDelogoor
S€e AltDeliv€ry,BaarWindowD€loggpr
See GroundDistribution,pag€ 1+5.
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tttlllnr ar-x,ver- | tn*t,".u IItI
orl "tol---riliii"--
inplt (backup)
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- -_-\Tgr?;u L
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requ€si
63-2
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