How do I Replace Printer Paper?
To replace the printer paper in the ED-18:

  •  Gently lift up on the finger tab to open the cover.
  •  Place a roll of paper in the cradle. Insert the paper through the slot in the cover as shown and close the cover.
   NOTE: Tear the paper along the edge of the plastic for a clean tear instead of pulling the paper straight out of the printer.


What is system noise?
System noise is usually caused by current flowing through the battery during testing. Make sure all electrical loads are OFF and the vehicle's doors are closed. Occasionally, a vehicle will have a high enough current discharged from the battery (key-off drain) that may remain ON for minutes after the vehicle is shut off. You should typically allow two to three minutes for the vehicle to test its on-board computer system. See Troubleshooting Test Problems.

How does the ED-18 test the alternator?
The ED-18 uses the latest electronic method of analyzing the alternator and does not require an amp probe. It analyzes five stages of alternator capability:
  •  No-load voltage (minimum current from the alternator)
  •  Loads-on idle (normal current applied, similar to stop-and-go traffic)
  •  No-load high RPM (testing voltage-regulation stability)
  •  Loads-on high RPM (re-evaluating with normal current loads applied)
  •  AC output from the alternator (through diode leakage)

When electrical loads are applied at idle and then at high RPM, a properly functioning alternator provides adequate current (amps) to the electrical loads while maintaining a high voltage level. With all normal vehicle loads on, the alternator is providing approximately 30 to 50 amps while sustaining a high and stable voltage level. The ED-18 will detect a weak or bad alternator that cannot sustain adequate voltage level.

TIP: Always apply constant electrical loads such as:
  •  Vent: high blower speed
  •  Head lamps: high beam
  •  Rear window defogger (if available)
  •  Inside courtesy lamps

Do not allow cyclic (on/off) electrical loads to operate during the test. They may spike higher than normal AC/DC voltage through the alternator. Cyclic loads include windshield wipers, air conditioning and the defroster. For example, turning on the air conditioning or defroster will start the A/C compressor, which turns on and off to regulate temperature. Instead, turn the HVAC selector to "vent" and turn on the high speed blower, which is a constant electrical load. Do not leave the vehicle doors open with the key in the ignition because doing so may also produce a cyclic load.

What do I do if I get a HIGH VOLTAGE or PHASE OPEN result?

Make sure that all cyclic loads are OFF. If the ED-18 displays either of these two results while all cyclic loads are OFF, use the ED-18's SCOPE function to verify the AC output at the alternator's B+ connection.

What if the ED-18 does not detect the RPM during the charging system test?
The ED-18 may not detect the RPM in some vehicles because of minimal charging voltage variation from idle speed to high engine RPM. Continue to test the charging system. If the analyzer will not allow testing to continue, make sure that all accessory electrical loads are OFF, then retest.

What's normal for the starting test?
The starting system test causes an initial drop in voltage (a drop in the discharge curve), which is normal and can often go down to approximately eight volts. This is an oscilloscope frame display of the initial starter engagement. Digital multi-meters will not capture this initial drop because their recognition speed is slower than that of the ED-18.

TIP: The vehicle battery should be near full charge before you conduct the starting and charging system tests. If the battery's state of charge is too low, it can produce erroneous starting-and-charging system test results.