14
R-2275
R-2285
CARRY OUT 3D CHECKS
Disconnect the leads to terminals 1 and 6. connect an ohmmeter across the terminals 1 and 6, a reading
of approximately 160 ohms should be indicated. If this is not the case then the relay coil is probably faulty
and the relay should be replaced.
CARRY OUT 4R TESTS
Relay contact test for short circuit:
CARRY OUT 3D CHECKS
Isolate terminals 3 and 5 of the surge relay. Using an ohmmeter, check continuity between terminal 3
and 5. A reading of infinite resistance should be obtained. If this is not the case then the relay is probably
faulty and should be replaced.
CARRY OUT 4R CHECKS
COMPONENT TEST
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
K
SURGE RELAY TEST
COIL
1
6
5
3
L
THERMISTOR (EXHAUST) TEST
CARRY OUT 3D CHECKS
Disconnect connector-B from the CPU unit. Measure the resistance of the thermistor with an ohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp. ............................................................. 20˚C - 30˚C
Resistance ........................................... Approx. 61.5k
Ω
- 39.5k
Ω
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS
THERMISTOR (AIR INTAKE) TEST
CARRY OUT 3D CHECKS
Disconnect connector-H from the CPU unit. Measure the resistance of the thermistor with an ohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp.
Resistance
15˚C ............................................... Approx. 3.14k
Ω
20˚C ............................................... Approx. 2.57k
Ω
25˚C ............................................... Approx. 2.11k
Ω
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS
M
MOTOR WINDING TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals.
Resistance of Blower motor should be approximately 32
Ω
.
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS
