Knock Sensor

I have a 96 Jimmy, 4.3L. The knock sensor is appearently not a GM part. Mine had two wires, and my shop tells me the proper part should only have one.
 
They told me to take it to the dealer. Has anyone come across this?
 
Thanks - Tom

I have a spare knock sensor from my 97 jimmy if you need it I will sell it cheap. want a pic of it?

Thanks, but not at this time. I'm not sure how to handle this 1 wire / 2 wire issue.

submit a pic of it if you can.  Never saw a knock sensor with more than one wire-wonder if what you are looking at is something else-some other sensor?  JP

It's at the dealer, and they have the knock sensor. It is the knock sensor, though. I have read that later 4.3L engines have a different knock sensor, and that those who have replaced their engines have had some issues with the knock sensor. I'm guessing that my 96 doesn't have the original engine