If you can move the battery out of the tray a bit but leave it hooked up...unbolt the Crank sensor on the top of the trans at about 1 oclock. Leave it plugged in and use a sharp electical probe to probe the weather pack connector being careful to slide it in next to the wire not into the insulation.
using a digital volt ohm meter like sears sells for twenty bucks and with the key on but engine not running...no prob right!...you should have nine volts on one wire, about 5 volts on another and next to nothing on the ground wire. hold something metallic up to the end of the sensor usually inside the trans...it should pull the 5 volts to zero. buy a new sensor if it is 9 ,0 and 0 and one of them pops up to 5 when you unplug it in the open air as described above.