User Manual

Table Of Contents

UT108/109 OPERATING MANUAL

3. Hall Switch/Sensor Testing (see gure 18)

When the tach and dwell are tested in the computer of the automobile, a Hall sensor is

used. The Hall sensor is normally used in the ignition system to detect the position of the

camshaft so that the computer of the automobile can set the optimal time for the ignition

and the opening of the fuel injector.

(1) Move the Hall sensor out of the automobile and see the details of the operation in

various kinds of automotive manuals.

(2) Connect the positive pole of the 9 V battery to the source end of the sensor and the

negative pole to the ground end of the sensor by referring the details to the positions of

the source and ground ends of the sensor in various kinds of automotive manuals.

(3) Set the rotary switch of the meter to Ω. Insert the red test lead into the Ω terminal and

the black one into the COM terminal.

(4) Connect the red and black test lead probes in parallel to the signal connect terminal

and ground end of the sensor and the meter should display a small ohm.

(5) When a metal plate (blade, steel tape, etc.) is inserted into a concave magnetic pole

of the sensor, the display of the meter will be enlarged or overloaded; if the metal

plate is moved away, the display will become smaller, which proves that the sensor is

satisfactory.