Hot wiring

About to take out and clean the NSS on my '96 Cherokee 4.0 and I want to learn how to do this hot wiring thing (bypassing the NSS switch) before I get her out in case something goes wrong. I've heard about it but haven't seen a good description on how to do it yet...something about removing a wire from somewhere and touching it to the + bat post with the key on and in park, then it starts. Can someone describe this a little better for me?

Not sure if its the same for all but my 96 i just unplug wiring conector next to trans dipstick tube and bridge the 2 pins which are closest to the retaining clip on the plug (if that makes sense) to activate starter. It can then be plugged back in or left out depending on how fussed you are bout having reverse lights but will start in any gear so be carefull it doesnt run away unexpectedly.
Its been quite a while since ive had to do it so not 100% sure i havnt forgotten anything.

Elsewhere I've been told that if I bypass my NSS I'll be risking overdrive lockup and torque converter lockup. What do these two conditions actually involve? We're not talking about that I could be driving along and my transmission locks up are we?

you'll be fine, i've had my NSS bypassed since 2004. If your cleaning of the NSS fails or you break it, you're not totally out of luck. on the connector, take a piece of small wire with the insulation stripped off, and put it inside the connector so it makes a connection between the two center pins on the side opposite of the clip that holds the two connector halves together. so if you hold it so the clip part of the connector is up, connect these two:

| | | |
| X X |

hope this helps. this only works on 96 and older XJs though, the later ones need the signal from the NSS for the computer to control the transmission correctly.

If all else fails just put the key in RUN and the shifter in park (MUST BE IN PARK UNLESS YOU FEEL LIKE RUNNING YOURSELF OVER!) and then crawl under the jeep with a wrench or something and jump the two posts on the starter together, it'll start.

I had to do this to get mine home one day when the ignition finally failed (the piece of the tumbler that actually hits the switch got broken off, and I couldn't turn it to START anymore) - fortunately I had already bought the new ignition switch + lock assembly, just hadn't installed it yet.

I have to jump the starter once out of every 20 or so starts, swapping columns (original column was very loose) didn't even fix it. Mine must be the NSS too.

I use a long screwdriver to jump mine, usually I have somebody hold the brake for me as a precautionary measure when I'm laying down there.