Honda Civic Service Manual page 791

Heating and Air Gonditioning
DTC Troubleshooting {cont'd)
DTC 12: A Problem in the Blower Motor
Circuit
' 1 .
C h e c k t h e N o . 1 2 ( 4 0 A ) f u s e i n t h e u n d e r - h o o d
fuse/relay box, and the No. 14 (10A) fuse in the
under-dash f use/relay box.
Are the tuses OK?
YES-Go to step 2.
NO Replace the fuse(s), and recheck.l
2. Connect the No. 2 terminal of the blower motor 2P
connector to body ground with a jumper wire.
BLOWER MOTOB 2P CONNECTOR
JUMPER ] BLU/BLK
Wire side ol female terminals
3 . T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
Does the blowet motor run?
YES Go to step 4,
NO Go to step 17.
4. Turn the ignition switch OFF.
5. Disconnect the jumper wire.
6. Disconnect the power transistor 4P connector.
21-20
8 .
7. Check for continuity between the No. 3 terminal of
the power transistor 4P connector and body ground.
POWER TRANSISTOR 4P CONNECTOR
Wire side ol temale terminals
ls there continuity?
YES-Go to step 8.
NO-Check for an open in the wire between the
power transistor and body ground. lf the wire is OK,
check for poor ground at G502.I
Connect the No. 1 and No. 3 terminals of the power
transistor 4P connector with a jumper wire.
POWER TRANSISTOR 4P CONNECTOR
Wire side of female terminals
T u r n t h e i g n i t i o n s w i t c h O N ( l l ) .
Does the blower motor tun at high speed?
Y E S - G o t o s t e p 1 0 .
NO-Repair open in the wire between the power
transistor and the blower motor.l
Turn the ignition switch OFF.
Disconnect lhe jumper wire.
9 .
1 0 .
1 1 .
2
3
4
BLK
o