1999 HONDA CIVIC fuse relay box

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

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