Mazda 626 Station Wagon, Workshop Manual, Page: 555 / 577

TROUBLESHOOTING
NO. 3 INDICATIONS OF CLIMATE CONTROL UNIT INDICATOR LIGHT ARE INCORRECT
3 Indications of climate control unit indicator light are incorrect.
DESCRIPTION Some indicator lights of switches on climate control unit do not illuminate, or their indications are
incorrect.
POSSIBLE
CAUSE
• Malfunction in A/C switch indicator light system (Steps 1, 2)
• Malfunction in rear window defroster switch LED system (Steps 3-10)
• Malfunction in other indicator light system (Step 11 )
Diagnostic procedure
• When performing an asterisked(*) troubleshooting inspection, shake the wiring harness and connectors while
doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If
there is a problem, check to make sure connectors, terminals and wiring harness are connected correctly and
undamaged.
STEP INSPECTION ACTION
1 INSPECT A/C SWITCH INDICATOR LIGHT
OPERATION
• Turn ignition switch to ON position.
• Turn both A/C switch and fan switch on.
• Does A/C switch indicator light illuminate?
Yes Go to next step.
No Go to Step 1 of troubleshooting index NO. 10.
2 CHECK AIR CONDITIONING SYSTEM
FUNCTIONS
• Are all of the air conditioning system functions
inoperative?
Yes Go to Step 1 of troubleshooting index NO. 2.
No Go to next step.
3
CHECK TO SEE WHETHER MALFUNCTION IS
IN REAR WINDOW DEFROSTER SWITCH LED
SYSTEM OR ELSEWHERE
• Does LED in rear window defroster switch
illuminate when switch is turned on?
Yes Go to Step 11.
No Go to next step.
4 CHECK FOR DTC 17 IN INSTRUMENT
CLUSTER
• Inspect rear window defroster switch LED
using instrument cluster input/output check
mode.
(See T-26 INSTRUMENT CLUSTER
INSPECTION)
• Does DTC 17 function properly?
Yes Go to next step.
No Go to Step 8.
*5 CHECK TO SEE WHETHER MALFUNCTION IS
IN REAR WINDOW DEFROSTER SWITCH
CIRCUIT OR ELSEWHERE
• Short climate control unit connector (16-pin)
terminal 2H and ground.
• Turn ignition switch to ON position.
• Does rear window defroster switch LED
illuminate?
Yes Replace climate control unit, then go to Step 12.
(Malfunction in rear window defroster switch
circuit)
No Undo short, then go to next step.
*6 INSPECT WIRING HARNESS BETWEEN
CLIMATE CONTROL UNIT AND INSTRUMENT
CLUSTER FOR CONTINUITY
• Turn ignition switch to LOCK position.
• Disconnect climate control unit connector
(16-pin) and instrument cluster connector
(20-pin).
• Is there continuity between climate control unit
connector (16-pin) terminal 2H and instrument
cluster connector (20-pin) terminal 3R?
Yes Go to next step.
No Repair wiring harness between climate control
unit and instrument cluster, then go to Step 12.
U-21