[blue thunder]

I put the starter relay mod in about five months ago and have had no problems starting the car since. Recently I have turned the key and got nothing randomly. Some days it starts fine. No click. The battery checked good so I checked the engine codes. I haven't been getting the check engine light on at all. I got code 11 and 12. I know there are two crank angle sensors. I am ready to order a new sensor but want to know where this one is located. Maybe a part number. Under the alternator? Are the two crank sensors different parts? Any guidance or help appreciated.

Mike