Hood HONDA CIVIC 1999 6.G Repair Manual

Heater Unit
Replacement
SRS components are located in this area. Review the
SRS component locations, precautions, and procedures
in the SRS section {24} before performing repairs or ser-
L Disconnect the negative cable from the battery.
2. Frcm under the hood, open the clamp, then discon-
nect the heater valve cable from the heater valve
arm. Turn the heater valve arm to the fully opened
position as shown.
When the engine is cool. drain the engine coolant
from the radiator (see section 10).
!@ Do not remove the radiator cap when
the engine is hot; the ongine coolant is under pres'
surg and could severely scald you.
CLAMP
HEATER VALVC CABLE
4. Disconnect the heater hoses from the heater unit.
CAUTION: Engine coolant will damage p8int.
Ouickly rinse any spilled engins coolant from painted
su aces,
NOTE: Engine coolant will run out when the hoses
are disconnected; drain it into a clean drip pan.
5. Remove the mounting nut from the heater unit.
NOTE: When removing the mounting nut, take care
not to damage or bend the fuel lines, the brake
lines, etc.
I x 1 .25 mm22 N.m {2.2 kgl.m, 16lblftl
21-39

Temperature Control
Adjustment -'96 - 98 Models
1. From under the hood, disconnect the heater valve
cable from the heater valve.
TERVALVECABLEHEATER VALVE ARM
2.From under the dash, disconnect the air mix control
cable housing from the cable clamp,
AIR MIXCONTROLARM
3.Set the temperature control lever to MAX. COOL.
With the air mix control cable attached to the air
mix control arm, gently pull on the outer cable
housing to fully close the door and to remove any
slack in the cable. Don't pullto hard, or the temper-
ature control lever will move.
Hold the air mix control arm against the stop. then
snap the air mix control cable housing into the
cable clamp.
21-44
6. From under the hood. move the heater valve arm to
the fully closed position. then attach the heater
valve cable to the heater valve arm.
7. Hold the heater valve arm in the closed position,
and gently pull on the heater cable outer housing to
take up any slack. then install the heater valve cable
housing into the cable clamp.
HEATER VALVE ARM

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

Wiring/Gonnector Locations
A/C DIODE.CONDENSER FAN RELAY,COMPRESSOR CLUTCH RELAY(Located in the under,hood fuse/relay box)
COND€NSER FANCONNECTOR
COMPARTMENTWIRE HARNESS
CONNECTOR
22-4

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

Condenser Fan
CONDENSER FAN RELAY 4P SOCKET
JUMPERwlRE
(cont'd)
22-9
Conden3er fan does not run at all.
Check the No. 56 (20 A) fuse in the
unde.hood frJse/relaY box, and the
No. 17 (7.5 A) fuse in the under-
dash fuse/relay box.
Reolace the fuse{s), and techeck
Remove the condenser lan rclaY'
and test it (see page 22 21i
Replace the condensei fan relav.
Check the under-hood tus6/relaY
Measure the vohage between the
No. 2 terminalofthe condenser fan
relav 4P socket and bodv ground.
ls there battery voltage?
Check the condenser lan Powersupply circuit:Connect the No. 1 and No. 2 teF
minals of the condenser fan relay
4P socket with a jumper wire
Does the condenser fan run?To page 22-10
Io page 22 11

Check the diode:1. Disconnect the iumPer wire
2. Remove the A/C diode from
the under hood fuse/relaY box
3. Check for current flow in both
directions between the A and
B terminals.
ls there current flow in onlY
one direction?
Chock for an open in the wire:
1. Turn the ignition switch ON(ll).
2. Measure the voltage between
the No. 2 terminal of the AJC
diode 2P socket and body
ground.
Repair opon in the wire betwe€n
the No. 17 luse and the A/c
diode.ls there battery voltage?
B()-=iFA
A/C DIOOE 2P SOCKET

Troubleshooting
Compressor
COMPRESSOR CLUTCH RELAY.P SOCKET
JUMPERWIRE
check the No. 56 (20 A) fuse in theunder'hood fuse/relay box, and theNo. 17 (7.5 A) fuse in the under,dash fuse/relay box.
Replace the fussls), and .echeck.
Remove the compressor clutchrelay, and test it {see page 22 21).
Check th6 und€r-hood tu3e/reby
Measure the voltage between theNo. 2 terminal of the compressorclutch relay 4P socket and bodyground.
Check the compressor clutchpow€r supply circuit:Connect the No. 1 and No. 2 termi-nals of the compressor clutch relay4P socket with a jumper wire.
Does the compressor clutch click?fo page 22-13
To page 22 14
22-12