? on Mr Hall Effect

[Clarence L.Snyder]

Bruce Plecan wrote:
> 
> In the past, I done some trouble shooting with Hall Effect Devises.
> Now, for the first time I hooked a meter to one with it sitting on the
> table.  The one I'm starring at is a Toyota, it has a red lead, a white
> lead, and a sheilded cable with ground.
>   So being the Cone Shaped Hat Wearer that I am, I did the following.  Using
> a 9v battery, I grounded it to the shell of the sensor
> applied + to the read lead, grounded the meter (DVM on V),
> hooked the meter's lead to the white wire, and then tested it.
> The test being held a gm crank disc near the tip of the toyota
> sensor.  The meter just flickers as I expose it to the metal?.
> I thought it would open and close as the metal came close to it?,
> yes/no?..
>   In various gm training references they show a pattern like
> 
>        ___       ___       ___       ___
> ___I      I___I     I___I      I___I      I
> 
> Can someone splain this to me, or refer me to an online source for
> accurate info?.
> Thanks
> Bruce
You sure it's Hall effect? What year and model?