Pinpoint Test D: The Speed Control Switch Is Inoperative

D1 CHECK THE SPEED CONTROL SWITCH OPERATION

Key in OFF position.
Disconnect: Speed Control Servo C122.

Measure the resistance between the speed control servo C122 pin 5, circuit 151 (LB/BK), harness side and the speed control servo C122 pin 6, circuit 848 (DG/OG), harness side, while pressing the speed control switch as follows:

SPEED CONTROL SWITCH RESISTANCE REFERENCE

Speed Control Switch	Resistance Value
Coast	Between 114 and 126 ohms
SET/ACCEL	Between 612 and 748 ohms
Resume	Between 2,090 and 2,310 ohms
Off	Less than 5 ohms

Fig 1: Measuring Resistance Between Connector Terminals

Courtesy of FORD MOTOR CO.

Are the speed control switch resistance values OK?

Yes : INSTALL a new speed control servo. REFER to SPEED CONTROL SERVO in his article. TEST the system for normal operation.
No : INSTALL a new speed control switch. REFER to SPEED CONTROL SERVO SWITCH in this article. TEST the system for normal operation.