1999 HONDA CIVIC dash

Troubleshooting -'99 - 00 Models
Symptom
Mode control motor does not run, or one or more modes are inoperat've'
Recirculation control door does not change between Fresh and Recirculate'
Blower motor only runs on high speed position; it does not run in any other speed positions
Blower motor does not run at all.
Both heater and Ay'C do not work
See pags
a1_tq
21-21
21-29
21-31
21 35
Symptom Chart
For electrical malfunctions which are indicated by the self-diagnostic system, refer to self-diagnosis function (see next
page).
Note these items before troubleshooting a symptom'
. Check the engine coolant level, and allow the engine to warm up before troubleshooting'
. Any abnormality must be corrected before continuing the test
.Becauseoftheprec|semeasurementsneeded,UseadigitaImu|timeterwithanoutputoflmAor|essatthe20ko
range when testing
. Before performing any troubleshooting procedures check:
- Fuses No. 41 115 Al, No 55 (40 A)]n the under-hood fuse/relay box' and No 17 (7 5 A) in the under-dash fuse/relav
box- Grounds No. G401, G402
- Cleanliness and tightness of all connectors
21-19

Mode control motor does not run.
or one or more modes arc inope]a-
tive.
Check the No. 17 (7.5 A) fuse in
the under-dash fuse/relay box.
Replace the Iuse. and recheck.
Check for an open in the wire:
1. Disconnect the mode control
motor 7P connector,
2. Turn the ignition switch ON (ll)-
3. MeasLrre the voltage between
the No. 1 terminal of themode control motor 7P con
nector and body ground
Repair open in the wire between
the No. 17 luse and lhe mode
control motor.ls there battery voltage?
Check the mode control motor:
1- Turn the ignition switch OFF
2, Test the mode control motor(see page 21 47).Check lhe mode control linkage
and doors:1. Remove the mode controlmotor (see page 21 47).
2. Check the mode control linkage
and doors for smooth move
ls the mode control motor OK?
Do the mode control linkage
and doors move smoothlY?
ReDlace the mode control motor'
Check for a short to Power in the
wires:1. Iurn the,gnitjon switch ON(ll).
2, Disconnect the heater controlpanel20P connector.3. Check for voltage betweenthe No. 2, 5, 6, 7, I and 9 ter'minals of the heater controlpanel 20P connector andbody ground individuallY.Repair shorl to power in the
wire{sl between the heater con-
trol oanel and the mode controlmotor. This short also damagesthe heater control Pan6l. RePair
the short to power before replac'ing the heater control Panel
ls lhere any voltage?
MODE CONTROL MOTOR 7P CONNECTOR
t2315
BLK/YEL
Wire side of female terminals
HEATER CONIROL PANEL 2OP CONNECTOR
Wire side of female terminals
NO
(cont'd)
21-25Io page 21 26

Recirculation control door does
not chango betwe€n Fresh and
Recirculate.
Check the No. l7 (7.5 A) fuse an the
underdash fuse/relay box.
Replace the fuse, and recheck.
Check lor an oPen in the wite:
1. Disconnect the recirculation
control motor 4P connector.
2. Turn the ignition switch ON (ll)
3. Measure the voltage between
the No. 1 terminal of the recir
culation control motor 4P
connector and body ground.
Repair open in the wire between
the No. 17 luse and lhe recircula-
tion control motor.ls there battery voltage?
Check the rccirculation control
motorr'] Turn the ignition switch OFF.
2. Test the recirculation control
motor (see Page 21 48i
Check the recirculation control
linkage and door:1. Remove the recirculation con_
trol motor lsee Page 2l 48).
2. Check the recirculation control
linkage and door for smooth
movement.
Reoair the recirculation conlrol
linkag€ or door.Do the recirculation control link_
age and door move smoothlY?
CONTROL MOTOR
side of temale terminals
RECIRCULATION CONTRC,lP CONNECTOR
q-?--T--T--T-|1l2l/l1l
f BLK/YEt(v)
!
page
(cont'd)

Blower Motor
BLOWER MOTOR 2P CONNECTOR
Wire side of lemale terminals
JUMPERWIRE
(cont'd)
21-31
Blower motor does not run at all.
Check the No. 55 (40 A) Iuse in
the under-hood fuse/relay box,
and the No. 17 (7.5 A){use in the
undeFdash fuse/relay box.
Boplace th€ fuse(3), and rechock.
Check th€ blow€r motor Powelsupply circuit:1. Disconnect the blower motor
2P connector.2. Turn the ignition switch ON {ll).
3, Measure the voltage between
the No. 1 terminal oI the blow
er motor 2P connector and
body ground.
ls there battery voltage?
Check tha blower motor:
1. Turn the ignition switch OFF
2. Reconnect the blower motor
2P connector.3. Connect the No.2 terminal o{
the blower motor 2P connector to bodv ground with a
tumper wire.4. Turn the ignition switch ON {ll}
Does the blower motor run?
fo page 21-32
To page 21-33

Both heater and A/C do nol work.
checkthe No.47 (7.5 A)fuse in the
under-hood fuse/relay box, and theNo. 17 {7.5 A) fuse in the under-
dash fuse/relay box.
ReDlace the tuse{s), and recheck.
Check lor an open in the wire:
1. Disconnect the heater controlpanel 8P connector,2. Turn the ignition switch ON (ll).
3. Measure the voltage between
the No. I terminal of the
heater control panel 8P con-
nector and body ground.
Repair open in the wire betweenthe No. '17 luse and th6 heatercontrol oanel,ls there battery voltage?
Check for an open in the wire:
1. Turn the ignition switch OFF.
2. Disconnect the heater controlpanel20P connector.3. Measure the voltage lletweenthe No. 10 terminal of theheater control Panel 20P con-nector and body ground.
Repair op6n in the wir€ between
the No. il7 tuse and the heater
controloanel,ls there battery voltage?
Check for an open in the wite:Check for continuity between theNo. 6 terminal of the heater con
trol panel 8P connector and bodyground.
Ch6ck tor an open in lhe wire
betwoen the heator control Paneland bodv ground. lf the wire isOK, check for poor ground atG401 and G402.
ls there continuity?
Check for looso wires or Poolconneciions at the heater controloanel 8P and 20P connectors. lf
the connections are good, substi'
tute a known-good heat€r con-trol Danel, and recheck. lI thesymptom/indication goes awaY,r6place the original h€ater con-troloanel.
HEATER CONTROL PANEL 8P CONNECTOR
BLK/YEL
Wire side of female terminals
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side of temale terminals
I2
1578
BLK
o
1
4I
v

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