[Roger Shultz]

To verify the operation of the sensor you must use an ohm meter instead of a voltmeter. If the sensor magnetic switch is working properly with an ohm meter across the two wires which you can access in the tunnel, you should see the resistance reading go from zero (a short) to infinity as the wheels are turned. You can jack the car up in the rear and do this or simply move the car while a helper looks at the meter to see what it is doing.

If that open and shorting action does not occur, then you will know in which direction the problem is occurring.