Pinpoint Test I: The Park Switch Not Working

Test Step

I1 CHECK CIRCUIT 15-TA34 (GN/YE) FOR OPEN

Disconnect: Transmission Shift Selector C307.
Key in ON position.
Measure the voltage between transmission shift selector C307 pin 3, circuit 15-TA34 (GN/YE), harness side and ground.

Fig 1: Checking Circuit 15-TA34 (GN/YE) For Open
Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?

Result / Action to Take

Yes

GO to I2.

REPAIR the circuit. TEST the system for normal operation.

Test Step

I2 CHECK FOR VOLTAGE ON CIRCUIT 8 -TA34 (WH)

Connect: Transmission Shift Selector C307.
Disconnect: Instrument Cluster C220b.
Select PARK.
Key in ON position.
Measure the voltage between instrument cluster C220b pin 8, circuit 8-TA34 (WH), harness side and ground.

Fig 2: Checking For Voltage On Circuit 8 -TA34 (WH)
Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?

Result / Action to Take

Yes

INSTALL a new instrument cluster. REFER to INFORMATION, GAUGES & WARNING DEVICES . TEST the system for normal operation.

GO to I3.

Test Step

I3 CHECK CIRCUIT 8 -TA34 (WH) FOR SHORT TO GROUND

Key in OFF position.
Disconnect: Transmission Shift Selector C307.
Measure the resistance between transmission shift selector C307 pin 8, circuit 8 -TA34 (WH), harness side and ground.

Fig 3: Checking Circuit 8 -TA34 (WH) For Short To Ground
Courtesy of FORD MOTOR CO.
Is the resistance greater than 10,000 ohms?

Result / Action to Take

Yes

GO to I4.

REPAIR the circuit. TEST the system for normal operation.

Test Step

I4 CHECK CIRCUIT 8 -TA34 (WH) FOR OPEN

Measure the resistance between transmission shift selector C307 pin 8, circuit 8 -TA34 (WH), harness side and instrument cluster C220b pin 8, circuit 8 -TA34 (WH), harness side.

Fig 4: Checking Circuit 8 -TA34 (WH) For Open
Courtesy of FORD MOTOR CO.
Is the resistance less than 5 ohms?

Result / Action to Take

Yes

INSTALL a new shifter harness. TEST the system for normal operation.

REPAIR the circuit. TEST the system for normal operation.