So, my sons 96 wouldn't start in park and only sometimes in neutral. It was also stuck in first gear and wouldn't shift up. It's an automatic. So I cleaned the nss switch and it not only fixed the starting problem, but the tranny started shifting normally again! Love fixing 2 things at once 👍!
This is the write up I used to fix the nss.
http://bc4x4.com/tech/2010/jeep-neutral-safety-switch-nss/

 

It wouldn't up shift out of first in 1-2 or drive? If in 1-2 it shouldn't up shift in to second until ~4k rpms. Up until I cleaned the NSS mine would up shift at no more than 2500rpm or less. Thought that was normal. Having thought that the first sign of my NSS having a problem was no back up lights I know now it was a wrong up shift issue.

 

Great write up! The gurus here have been saying this for years now. Hard to believe they would engineer it like this, and probably shouldn't have, but they did.

 

I have driven my 97 and a 96 with the nss jumped and it didn't cause any shifting problems. Just no cruise control or reverse lights, and it would start in any gear.

 

My '96 would never stay in 1st up to ~4k rpm when in 1-2 until I reworked the NSS. As far as knowing I had a NSS issue I lost backup lights. Then intermittent to no start in park. Then intermittent no start in neutral.