Suzuki RA410 Manual page 409

6E1-44 ENGINE AND EMISSION CONTROL SYSTEM
TABLE B-9 A/C CONTROL SIGNAL CHECK (IF EQUIPPED)
1. Battery
2. Main fuse box
3. Ignition switch
4. Circuit fuse
5. Blower fan motor
6. Blower fan switch
7. A/C switch
8. Dual pressure switch
9. A/C evaporator thermistor
10. A/C compressor
11. ECM/PCM
12. To other sensors
TERMINAL ARRANGEMENT OF ECM/PCM CONNECTOR (VIEWED FROM HARNESS SIDE)
C11
C21 C20
STEP
1 1) Disconnect ECM/PCM connectors with ignition switch
at OFF position.
2) Check resistance between "A4" terminal and "C14"
terminal.
3) Is it within specification?
Reference value
(Refer to characteristic curve below)
At 0 C
At 25 C
2 1) Check voltage at "C21" terminal under each condi-
tion given in table below.
Ignition switch ON
A/C switch OFF
Ignition switch ON
A/C switch ON
NOTE:
When A/C evaporator thermistor temp. is below
2.5 C (36.5 F), A/C remain OFF ("A12" terminal
voltage become 0 – 1 V). This condition is not
abnormal.
2) Is check result satisfactory?
C1
C14
ACTION
6.3 – 6.9 k
1.8 – 2.2 k
Go to step 2.
Go to step 3.
10 – 14 V
0 – 1 V
YES
Faulty A/C evaporator
thermistor or its circuit.
"Bl/R" wire open or
short
Poor "C21" terminal
connection
If wire and connection
are OK, substitute a
known-good ECM/
PCM and recheck.
Go to step 3.
A4
A13 A12
NO