1999 HONDA CIVIC heater

Adjustment -'99 - 00 Models
1. From under the hood, open the cable clamp, then
disconnect the heater valve cable from the heater
valve arm.
From under the dash. disconnect the heater valve
cable housing from the cable clamp, and disconnect
the heater valve cable from the air mix control arm.
HEATER VALVE CABLE
Set the temperature control dial on MAX COOL with
the ignition switch ON {ll).
Attach the heater valve cable to the air mix control
arm as shown above. Hold the end of the heater
valve cable housing against the stop, then snap the
heater valve cable housing into the cable clamp.
HEATER VALVE ARM
5. From under the hood. turn the heater valve arm to
the fullv closed oosition as shown, and hold it,
Attach the heater valve cable to the heater valve
arm, and gently pull on the heater valve cable hous-
ing to take up any slack, then install the heater valve
cable housing into the cable clamp.
HEATER VALVE ARM
21-45

RelaysHeater Fan Switch
Test
There should be continuity between the No 1 and No. 3
terminals when power and ground are connected to the
No.2 and No. 4 terminals, and there should be no conta-
nuity when power is disconnected.
Blower motor relaY
. Blower motor high relay ('99 00 models)
,I It;€'Y )
Test -'96 - 98 Models
Check for continuity between the terminals according to
the table below.
lerminal
Position14253
OFF
1IrJ
2o-o
3o-a
4c)-{
21-49

Circuit Diagram
UNDER DASHFUSE/RELAY 8OX
N0.17 (7.54)
'96 - 98 Models
UNDER.HOOD FUSEi BELAY BOX
WHT/SLU BLKYEL
BLK
+
G751
3
'o
I8LK
I
G40lG402
GNITON SWITCH
N0.41 (8rA) N0.42 (40A)
COMPBESSORCLUTCHBELAY
BLUMHT
,l
(E) i,T'
BLUi BED
A/c ITHERMOSTAI BLU/REO
CONDENSEFFAN MOTOR
*F,.X,
FAN rl
BLK
{
G401G402
HEATERswrlcH
32
22-6

'99 - 00 Models
UNDER DASHFUSE/BELAY BOX
No.l7 (7.54)
BLK
I
G751
$*"
O :8P coNNEcToF
n :20P CONNECToF
E 12P coNNEcroRBLK
d-
G401G402
UNDER HOOD FUSE/RELAY 8OX
N0.41 (P,0A) N0.42 (404)
COMPRESSORCLUTCHFELAY
GNITON SWTCH
HEATER CONTROL PANEL
22-7

Troubleshooting
Symptom Chart
NOTE:
. Any abnormality must be corrected before continuing the test.. Because of the precise measurements needed. use a multimeter when testinq.. Before performing any troubleshooting procedures check:- Fuses No. 47 l7 -5 Al, No. 56 (20 A) in the under-hood fuse/relay box, and No. 17 (7.5 A) in the under_dash fuse/relavbox- Grounds No. c401, c402, G751- Cleanliness and tightness of alt connectors
SymptomRemedy
Condenser fan does not run at all.Perform the procedures in the flowchart {see page 22-9).
Compressor clutch does not engage.Perform the procedures in the flowchart lsee page 22-12).
Ay'C system does not come on (compressor and fan),Perform the procedures in the flowchan (see page 22-17).
Both heater and A,/C do not work.. '96 - 98 models-Perform the procedures in the flowchart
{see page 21-18).. '99 - 00 models-Perform the procedures in the flowchart(see page 21-35).
22-8

Ftom page 22 18
Check tor an open in the wire:1. Turn the ignition switch OFF,then disconnect the iu mper
2. Remove the center dashboardlower cover lsee section 20),
and disconnect the heater con'
trol panel 14P connector.
3. Turn the ignition switch ON (ll).
4. Measure the voltage betweenthe No. 11 terminal and bodyground.
Repair op6n in the wire bstween
the A/C th€rmostat and th6 hoater
control panel.
Check lor an open in the wire:
1. Turn the ignition switch OFF.2. Disconnect the heater Ian
switch 6P connector,3. Check for continuity between
the No. 14 terminal of theheater control panel 14P con_nector and the No.6 terminalof the heater fan switch 6P con-nector.
Repair open in the wiro betweGnthe heal.r control Panel and theheater fan switch.
Check for an open in thG wire:Check for continuity between theNo. 1 terminal of the heater lanswatch 6P connector and bodYground.
Chock tor an open in tho wir€
between the heater lan switch
and body ground. lf the wire is OK,check for poor ground at G401 sndG402.
ls there continu;ty?
ReDlace the heater tan switch.ls the heater fan switch OK?
Check for loose wiaes or poor
connections at the heater controloanel 14P connoctor and hoetertan 3witch 5P conn€clor and atthe A/C thermostet 3P connec-tor. ll the connections are good,
raplace the heator control Panel.
r'oA - qe m^.lalal
HEATER CONTROL PANEL lilP CONNECTOR
tra6
7II'o lx't1121314
BLU/RED
Wire side of female terminals
HEATER CONTROL PANEL 1'P CONNECTOR
Wire side of female terrninals
HEATER FAN SW]TCH 6P CONNECTOR
Wire side of female terminals
(cont'd)
12;--?45
7I10X'll121314
GRN
123
a56GRN
22-19

Troubleshooting
('99 00 models)
From page 22 18
Check lor an open in the wire:1. Turn the ignition switch OFF,then disconnect the ju mper
2. Disconnect the heater controlpanel 20P connector.3. Turn the ;gnition switch ON{

i.4. Measure the voltage betweenthe No. 11 terminal of theheater control panel 20P con-nector and body ground.
Ropai. opan in tho wira batwaonthe A/C thermostat and thehoater control oanol.ls there battery voltage?
Check the push switch:1. Turn the ignition switch OFF.2. Disconnect the push switch12P connector.3. Check for continuity betweenthe No. I and No. 10 terminalsof the push switch 12P con-nector with the A/C switch ON.
Check for loose wi.es or poor
connections el the hgater controlpanel 20P connector and pushswitch 12P connector and at theA/C thermostat 3P connector. Ittha connections are good, substi-tute a known-good heatea con-trol pan€|, and recheck. lf thesymptom/indication goe3 away,replace lhe original healer con-trol oan€|,
HEATER CONTROL PANEL anP CONNECTOR
Wire side of temale terminals
PUSH SW]TCH 12P CONNECTOR
Wire side of female terminals
,/1,/156
7819t01112
I
I
I

A/C System Service
Performance Test
The performance test will help determine if the air con-
ditioner system is operating within specifications.
Use only service equipment that is U.L.-listed and is cer-
tified to meet the reouirements of SAE J2210 to remove
HFC-134a (R-134a) from the air conditioner system.
CAUTION: Exposure to air conditionor rofrigerant and
lubricant vapor or mist can irrilalo €yes, nose and
throat. Avoid breathing tho air conditioner rstrigerrnt
and lubricant vapor or mist,
lf accidental system discharge occurs, ventilate work
area before resuming service.
R-134a service equipment or vehicle air conditioner sys-
tems should not be pressure tested or leak tested with
compressed air.
@ some mixtur$ of air and R-134a have been
shown lo b9 combustible rt glgvatad pr€ssur63 and can
resull in tire 01 oxplosion causing inlury ot property
damage. Never uao compre33ed air to pressure t99t R-
134a ssrvico 6quipmsnt or vohicla air conditioner sys-
tems.
Additional health and safety information may be obtained
from the refrigerant and lubricant manufacturers.
'1. Connect a R-134a refrigerant recover/recycling/
charging station to the vehicle, as shown, following
the equipment manufacturer's instructions.
2. lnsert a thermometer in the center vent outlet.
Determine the relative humidity and air tempera-
ture,
Test conditions:
. Avoid direct sunlight.
. Open hood.
. Open front doors.
. Set the temDerature control lever or dial to MAX,
COOL, the mode control switch or dial on VENT
and the recirculation control switch on RECIRCU-
LATE.
. Turn the A,/C switch on. and the heater fan switch
on MAX.
. Run the engine at 1,500 rpm.
. No driver or passengers in vehicle
After running the air conditioning for 10 minutes
under the above test conditions, read the delivery
temperature from the thermometer in the dash vent
and the high and low system pressure from the A,/C
gauges.
Recovery/Rocycling/Charging Station
22-24