Ford 2003 Mustang Workshop Manual page 3909

Is the voltage greater than 10 volts?
A3 CHECK CIRCUIT 588 (VT) FOR AN OPEN
Key in OFF position.
Connect: Convertible Top Switch C3115.
Disconnect: Raise Relay C4063.
Key in ON position.
Depress and hold the convertible top switch in the RAISE position.
Measure the voltage between raise relay C4063 pin 85, circuit 588
(VT), harness side and ground.
Is the voltage greater than 10 volts?
A4 CHECK CIRCUIT 688 (GY/LB) FOR VOLTAGE
Key in OFF position.
Disconnect: Lower Relay C4064.
Key in ON position.
Depress and hold the convertible top switch in the LOWER
position.
Measure the voltage between lower relay C4064 pin 85, circuit
688 (GY/LB), harness side and ground.
Is the voltage greater than 10 volts?
A5 CHECK CIRCUIT 588 (VT) FOR OPEN
Key in OFF position.
Disconnect: Convertible Top Switch C3115.
Measure the resistance between convertible top switch C3115 pin
3, circuit 588 (VT), harness side and raise relay C4063 pin 85,
Yes
GO to A4 .
No
GO to A5 .
Yes
GO to A9 .
No
GO to A8 .
Yes
INSTALL a new
convertible top switch.
REFER to Convertible