TROUBLESHOOTING
G-25wiring diagramK8-specific two-speed condenser fan control using three relays. Low speed: relay No.1 ON only (coolant above 100°C). High speed: all three relays ON (coolant above 108°C).
Flowchart No. 7
7
DetailSymptom: Engine overheats at high load; A/C operates normally [K8]
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DetailRelated components: ECM, condenser fan, condenser fan relay No.2, condenser fan relay No.3, wiring harness
Condenser fan two-speed control circuit [K8]
Components (8)
A/D FAN 40A fuseREAR WIPER 10A fuseCondenser fan relay No.1Condenser fan relay No.2Condenser fan relay No.3Condenser fan motorECMGROUND
Connections (10)
A/D FAN 40A fuse
A/D FAN 40A fuse:+BCondenser fan relay No.2:contactBlue with Yellow stripe
REAR WIPER 10A fuse
REAR WIPER 10A fuse:IG2Condenser fan relay No.2:coilGray
REAR WIPER 10A fuse:IG2Condenser fan relay No.3:coilGray
Condenser fan relay No.2
Condenser fan relay No.2:contact-outCondenser fan relay No.1:inBlue
Condenser fan relay No.2:coil-outECM:P/BRed with Yellow stripe
Condenser fan relay No.1
Condenser fan relay No.1:L/RCondenser fan motor:M1Blue with Red stripe
Condenser fan relay No.1:LCondenser fan motor:M2Blue
Condenser fan motor
Condenser fan motor:M3GROUND:GNDBlack
Condenser fan motor:M4Condenser fan relay No.3:contact-outBlue with Green stripe
Condenser fan relay No.3
Condenser fan relay No.3:coil-outECM:inRed with Yellow stripe
Normal Operation
To keep the engine from overheating, engine speed is controlled in two phases by combining condenser fan operation and engine coolant temperature as shown below. This operation is controlled by the condenser fan relay No.1, condenser fan relay No.2, and condenser fan relay No.3.
Condition
Condition
Low
Condenser fan relay No.1ON
Condenser fan relay No.2OFF
Condenser fan relay No.3OFF
Engine coolant temperatureabove 100°C {212°F}
High
Condenser fan relay No.1ON
Condenser fan relay No.2ON
Condenser fan relay No.3ON
Engine coolant temperatureabove 108°C {226°F}