Anybody know what kind of switch is bad or going bad? Some times when my 91 xj is in park it won't start. I can sometimes wiggle the shifter and it starts right up. Sometimes I have to shift it to neutral. I'm pretty sure it's some type of switch that tells it that it's in gear and not to start, but I don't know what it is. What is it??

 

Neutral safty switch. Replaced one in my cousins 1990 cherokee, and i susgest to by pass it. Hers cost her like 100 bucks and I had a hard time replacing it.

 

where is this neutral sensor??

 

it is underneath jeep on passengers side of transmission. You can get one at teamcherokee for around $129 plus shipping, the cheapest I have found and is made by crown motor. Youll have to soak bolts good to get it out with rust remover or something like that.

 

I would suggest removing it, pulling it apart and cleaning it and see if it works better.

 

how would I bypass it?

 

I wouldnt bypass it as it works your b/u lights and also o/d on the trans.

Its very easy to get off with only one bolt and a nut holding it on. Best thing to do is clean all the mud and grime off of it and spray it with some type of lube before trying to get it off.
Its only a hours job to take it apart and clean it and reinstall.
all you need is a can of contact/electrical cleaner (dont use brake or carb cleaner as some of it will destroy the plastic) a small piece of emery cloth or fine sand paper and a cpl of dabs of dielectric grease sold at any auto parts store.

 

Pull the NSS off and clean it up inside. If this doesn't work get one off a donor XJ in the JY. No need to pay the rediculous price of a new one. I tried the clean up method on mine. It was good for about a month then randomly started to not start in P, again. It starts everytime in Nuetral and after wiggling the shifter it will start in Park so, I'm good for now. but, on the look out for a decent looking switch to grab from a donor rig in the JY.

 

my 91 I just sold did the same thing. I would have to push forward on the shifter while in Park to get it to start sometimes.

 

Agree you shouldn't pay for a new one if you don't have to. I found a good one on e-bay for about $40 for my 87. I tried cleaning the old one a couple of times with limited success. You could bypass by installing a jumper directly from the starter relay ground connection to the chassis, however, as pointed out in the string, if your NSS is going bad, the back-up lights probably also aren't working. Before I finally changed my NSS switch, I used to carry a short jumper wire with a couple of alligator clips so I could bypass the NSS switch on short notice when needed.

 

i have this problem too, and like someone said before my backup lights also wont work... so where exactly is the nss located? and how does it look?

 

Passenger side of the transmission casing. It has an electrical lead that's about 2-ft long. The wiring connector is toward the rear of the passenger side engine compartment. Also, the main nut holding the switch in place can be loosened and the switch can be rotated a few degrees either direction to get it properly adjusted. You should be able to get a solid ground through the switch when the transmission is in park or neutral. It is helpful to have a wiring diagram to know which lead you need to check. If you have trouble finding the switch, I can snap a picture of the old one I pulled off my 87. Sometimes I have trouble parting with junk...

 

this post is on time as my 91 failed to start last nite,wasnt the first time but now i need to pay for a tow.Im not the best with electrical problems but i feel with the info posted here i should have no problem removing the nss

 

If you pull it to clean it, use electrical contact cleaner. Brake parts cleaner may damage the circuits inside. After cleaning out the funk, use a fine grain emory paper to clean the contacts to remove corrosion. Then make sure you repack it with dielectric gel to prevent moisture and dirt from causing more corrosion. You should be able to get everything at any parts store for around 15 to 20 bucks.