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Verify the horn and brake light operation. Service as necessary if either is not working properly. Backprobe the Light Blue/Black wire at the servo connection and check for battery voltage when holding the speed control On button down and the ignition switch in the Run position. Voltage should indicate to be battery voltage. Release the On switch, the voltage should now read approximately 6.0-7.5 volts which is fed to the switches from the servo. Pushing the Set/Accel button should cause this voltage reading to decrease to approximately 4.0-5.0 volts. Holding the OFF button should cause the voltage to drop to less than 0.5 volts. If there is no voltage out of the LB/BK wire, verify that the Red/Light Green wire at pin 9 of the servo will illuminate a standard 12-volt test light or a heavy load such as a headlight bulb. If the RD/LG wire does not carry enough amperage to illuminate the load, check the deactivator switch for a connection problem or defective switch. The deactivator switch is on the front of the master cylinder. Pull the connector off of the switch and inspect the switch for the presence of brake fluid which may have bled through the connector. If the speed control input switches show proper value, check for battery voltage on the Violet/Orange wire at pin 7 which is fed from fuse 6 (10 amp) of the Central Junction Box. Check for a Vehicle Speed Sensor input signal on the Grey/Black wire at pin 3. This circuit will show an AC square wave signal with the rear wheels spinning and is provided from the Powertrain Control Module. If all signals appear to be correct, inspect the linkage for binding, and if OK, replace the servo.
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