Jeep wont start when warm

I have an 89 Jeep Cherokee with a 4.0 liter engine. It will start fine when the engine is cold, but after I run it for 15 minutes or longer it will not start back up. When I turn the key the motor does'nt turn over, It does'nt click or make any kind of noise. The accesories inside the jeep will still work. If I wait 10-20minutes it will start again. I have replaced the ignition switch, starter, and starter relay and it did'nt fix the problem. Any ideas would be great.

I took the nss switch off the jeep. Took it apart and cleaned it and greased it. This seems to have fixed the problem. If anyone wants to know.

I took the nss switch off the jeep. Took it apart and cleaned it and greased it. This seems to have fixed the problem. If anyone wants to know.

What and where is the NSS Switch?

Hi,

NSS = Neutral Safety Switch. This switch is ONLY found on an automatic transmission. It is actually several switches in one unit, and a common problem on automatic Jeeps. :D

As to where on the transmission it is, I have no clue, as I never have and probably never will own an auto Jeep :grinno:

-Nick

typically the CPS is the culprit as it takes over when the engine is warmed up. 1st 15 minuet the engine runs without the CPS active. But once the engine warms up the CPS activates. Could it be that a loose connection was found??? in any event, thought i'd post as a second possible solution.