Ford 2003 Mustang Workshop Manual page 3301

Is the voltage greater than 10 volts?
V3 CHECK RUN/START POWER SUPPLY TO THE
INSTRUMENT CLUSTER
Key in OFF position.
Disconnect: Instrument Cluster C220b.
Key in ON position.
Measure the voltage between the instrument cluster C220b
pin 12, circuit 20 (WH/LB), harness side and ground.
Is the voltage greater than 10 volts?
V4 CHECK GROUND CIRCUIT 397 (BK/WH) FOR AN OPEN
Key in OFF position.
Measure the resistance between the instrument cluster
C220b pin 20, circuit 397 (BK/WH), harness side and
ground.
Is the resistance less than 5 ohms?
V5 CHECK GROUND CIRCUIT 1205 (BK) FOR OPEN
Measure the resistance between the instrument cluster
C220b pin 1, circuit 1205 (BK), harness side and ground.
No
REPAIR the circuit. TEST
the system for normal
operation.
Yes
GO to V4 .
No
REPAIR the circuit. TEST
the system for normal
operation.
Yes
GO to V5 .
No
REPAIR the circuit. TEST
the system for normal
operation.
Yes
GO to V6 .
No
REPAIR the circuit. TEST
the system for normal
operation.