1999 HONDA CIVIC Blower

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

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

BIower Motor Speed
To page 21 30
NOTE: lf the blower motor does not
run at all, refer to page 21-31.
POWEB TRANSISTOR 3P CONNECTOR
BLK
Wire side ol female terminals
JUMPERWIRE
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side of female terminals
LT GRN/8LK
(cont'd)
21-29
Blower motor only runs on high
speed position; it does not run in
any other speed Positions
Check for an open in lhe wire:
1. Disconnect the power transis
tor 3P connector,2. Check for continuity between
the No. 3 terminal of thepower transistor 3P connector
and body ground.
Check tor an open in the wire
between the Power ttansistor
and body gtound. lf the wire is
OK, check for poor ground at
G401 and G402.
ls there continuity?
Check tor an open in the wire:
1. Connect the No. 1 and No 3
terminals of the Power tran_
sistor 3P connector wlth ajumper wire.2. Turn the ignition switch ON {ll)
Repair open in the wire belweenthe blower motor and the Powettranststor.
Check tor an open in the wire:
1. Turn the ignition switch OFF
2. Disconnect the iumPer wire.
3. Disconnect the heater controlpanel 20P connector.4. Check for continuity between
the No. 1 terminal of the
heater control panel 20P con-
nector and the No. 2 terminal
of the Power transistor 3P
Repair open in the wire between
the heater control Panel and tho
oower transistor,ls there continurty)
3
o

Troubleshooting -'99 - 00 Models
Blower Motor Speed (cont'dl
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side oJ female terminals
Wire side ot female terminals
Frcm page 21.29
LT GRN/BLK
Check tor a short in the wi.a:Check for continuity between theNo. 1 terminal of the heater control panel 20P connector and bodyground.
Repair short in ths wire betwsenthe hoater control panel and theoower transastoa.
Check for an open in the wire:1. Disconnect the heater controlpanel 8P connector,2. Turn the ignjtion switch ON 1ll).3. Measure the voltage betweenthe No. 'l terminal of theheater control panel 8P connector and body ground.
Repeir open in the wiio betweenthe heater control panel and theblower motoa.
Check the power transistor:1. Turn the ignition switch OFF.2. Reconnect the heater controlpanel 8P and 20P connectors.3. Test the power transistor {seepage 21 50).
ls the power transistor OK?
Check for loos€ wiras or poor con-nections at the h€at€r controlpanel 8P and 20P connectols andat th6 power transistor 3P conn€c-tor. lf the connections are good,substituto a known-good hoatercontrol panel, and recheck. It thesymptom/indication goes away,replace the original heater controloanel,
HEATER CONTNOL PANEL 8P CONNECTOR
21-30

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

Troubleshooting -'99 - 00 Models
From page 21-31
Check the blower motor relay:1. Turn the ignition switch OFF.2. Remove the blower motorrelay from the under hoodfuse/relay box, and test it- (seepage 21'49).
Replace the blower motor relay.
Check the under-hood tuse/relaybox:Measure the voltage between theNo. 3 terminal of the blowermotor relay 4P socket and bodyground.
Check tor an open in the wire:1. Turn the ignition switch ON (ll).
2. Measure the voltage betweenthe No. 4 terminal of theblower motor relay 4P socketand body ground.
Repair opon in lhe wire betweenthe No. 17 fuse and the blowetls there battery voltage?
Check for an open in the wire:1. Turn the ignition switch OFF.2. Check for continuity betweenthe No. 2 terminal of theblower motor relay 4P socketand body ground.
Check lor an ooen in the wirebetween the blowor motor relayand body ground. It the wiie isOK, check for poor ground atG401 and G402.
ls there continuityl
Repair open in the BLU/WHTwiae between the blower motorrelay and the blower motor,
BLOWER MOTOR RELAY 4P SOCKET
21-32

From page 21 31
ls there continuity?
YES
Check the blower motor highrelay:1. Turn the ignition switch OFF,and disconnect the iumPer
2. Remove the blower motor
high relay, and test it. {seepage 21 49).
Check lor an open in the wire:1. Connect the No. 1 terminal ofthe blower motor high relay4P connector to body ground
with a jumPer wire.2. Turn the ignition switch ON (ll).
Repair open in the wire belweenthe blower motor and the blowermotor high rolay.Does the blower motor run?
Check for an op6n in the wir6:1. Turn the ignition switch OFF,and disconnect the iumPer
2. Turn the ignition switch ON (ll).
3, Measure the voltage betweenthe No. 2 terminal of theblower motor high relay 4Pconnector and body ground.
Repair open in the wire betweenthe No. 17 fuse and the blowor
motor high relay.ls there battery voltage?
Check for an open in the wire:1. Turn the ignitaon switch OFF.2. Check for continuity betweenthe No.3 terminal of theblower motor high relay 4P
connector and body ground.
Ch6ck lor an op.n in the wirebotween the blower motor highrelay and body ground. ll the wireis OK, ch6ck for poot ground atG401 end G402.
To page 21 34
BLOWER MOTOR HIGH RELAY 4P CONNECTOR
JUMPERWIRE
Wire side of female terminals
(cont'd)
21-33