HARNESS AS-ENGINE 3994015 - Caterpillar

adjustment screw.2. Use a small screwdriver and lightly turn oil step adjustment potentiometer twenty turns in the direction of "MAX ARROW" (counterclockwise). This will lower the oil step speed setting to its lowest value. The oil step adjustment screw is made so it cannot cause damage to the potentiometer, or be removed, if the adjustment screw is turned too many turns in either direction.3. Use a 6V7070 Multimeter (or a voltmeter of same accuracy) to check for positive (+) voltage at terminal ESS-13 [negative (-) voltage is at terminal ESS-5].4. Make reference to SPEED SPECIFICATION CHART (in Service Procedure A). For a particular engine rating, find the specified rpm in column for Oil Step Speed Setting. Run the engine at this specified rpm.5. With the engine running, look into the oil step adjustment access hole. A red "LED" (light emitting diode) light will be ON. A positive (+) voltage will be seen at terminal ESS-13, 9 seconds after "LED" light comes ON. Now turn the oil step adjustment potentiometer clockwise until the red light in the oil step access hole goes OFF. When the light goes OFF, this indicates that the oil step rpm setting is above the present running rpm of the engine.Service Procedure E
Magnetic Pickup Check
1. Connect a 6V7070 Multimeter (or a voltmeter of same accuracy) to electronic speed switch common terminal (ESS-3) and signal terminal (ESS-4). Set the meter voltage scale to a scale greater than 1.5 VAC. Start the engine and run at idle rpm or 600 rpm (whichever is greater).If the measured voltage is 1.5 VAC or more, the operation of the magnetic pickup is correct. If measured voltage is less than 1.5 VAC, go to Step 2.
The magnetic pickup is an important part of the ETR Shutoff Protection System. It is required for crank terminate, overspeed and governing. Be ready to take action when the magnetic pickup is disconnected.
2. Stop the engine. Disconnect the wiring from the magnetic pickup at the plug-in connector and connect the voltmeter to magnetic pickup connector terminals. Start the engine and run at idle rpm or 600 rpm (whichever is greater).If the measured voltage is 1.5 VAC or more, repair or replace the wiring between the magnetic pickup and the electronic speed switch. If the measured voltage is less than 1.5 VAC, go to Step 3.
Magnetic Pickup (Typical Example)
(1) Clearance dimension. (2) Locknut.3. Remove the magnetic pickup from the engine flywheel housing and turn the flywheel until a gear tooth is directly in the center of the threaded opening for the magnetic pickup. Install the magnetic pickup again in the threads of the flywheel housing.4. Turn (by hand) in a clockwise direction until the end of the magnetic pickup just makes contact with the gear tooth. Now turn the magnetic pickup back out 1/2 turn (180 degrees in the counterclockwise direction) to get the correct air gap [clearance dimension (1)]. Now tighten locknut (2) to a torque of 45 7 N m (33 5 lb