Does anyone know how to test the crank sensor on evo8/9.
I know is a hall effect type...

 

on a audi 20v "A better test for the Hall Effect Sensor, is to make up a "low voltage" LED test light (LED with 120 ohm resistor in series) and connect the positive (+) side of the LED test light to terminal 1 (Red/Black wire) and the negative (-) side of the LED test light to terminal 2 (Green Wire) of the hall effect connector. This test is done with the connector plugged on to the distributor connector, and by pulling the rubber boot back off the connector to allow back probing the connector terminals.



The low voltage LED test light should flicker on/off when you crank the engine over during starting to indicate the hall effect sensor inside the distributor is working correctly.

 

the Evo sensor has a blue, red and black

 

i hooked mine up to a power supply and an oscilloscope, then waved a piece of metal over it and made sure i got square wave output.

 

Am I correct in saying, Black wire= ground or - negative, Red wire: constant +12V
Blue wire= Signal wire that must give the 5V +-0.5V... square wave?

 

yup sounds good.
not sure if it was 5V out or 12V out. Was a while ago now