My 1999 cherokee with auto trans sometimes will not start unless I jiggle the shifter. I assumed it was the NSS. I was starting it that way for about a month and then one day my battery was dead so I bought a new battery. Jeep started every time for a few weeks then the same problem returned. after a week of jiggling the shifter to start it the new battery was dead and needed a jump. Can the NSS being bad somehow drain the battery or do I have 2 problems here? I ordered a new NSS and will be replacing it this weekend. BTW I tested the alternator with the jeep running and it checks out OK.

 

Sound like to me that you do have to separate problems. You might have a parasitic draw on the system. Here's a video that shows how to check it out.
Also here's a link on how to clean you NSS.
http://www.bc4x4.com/tech/2010/jeep-...ty-switch-nss/

 

Agree with Robert.
The dead (new) battery, with alternator charging on-car tested, is suggestive for a drain. The NSS would not be likely draining it, unless it drains in a weird short way, which I would not see how.
The new NSS (you can do a clean of the one you have now, but since you already ordered it, that's for future reference) and that video (which is a good one as well as his testing alternator and charging systems) will give you a lot more info and with a bit of luck, the solution.