So I guess I should try shifting while driving I thought it had to be stopped when shifting so I would stop put tranny in netraul shift to 4x4 then shift then back to drive and go i'll try while moving

 

Okay I tried while driving and here is what I got I drove at normal speed changed from 2H to 4H and really felt no change and no light came on I then slowed down to about 2 mph and shifted to 4L which still no light but felt a big change it seemed to get a little jerky when I let off gas I was on dry pavement almost like if you were to downshift. (I really don't know how to explain it) and take off had more power felt like if I shifted into 2-3 instead of drive on take off (but I was still in drive)

 

Sometimes no light comes on and then 10 feet down the road the fulltime light will kick on. Sometimes the parttime light will come on and 10 feet down the road it will switch to Full time. Sometimes it goes straight to full time. So far it's completely random, but it always finally switches over after a push of the throttle and rolling a few feet.

 

Make sure you have the correct Transmission to do this. The Command Trac does not seem to like being swapped over during driving while the Selec-Trac doesn't care. Request a build sheet from Chrysler to confirm what yours came with. If it's been replaced then I don't know how to verify the difference.

 

new jeep owner its a 91 Cherokee 4wd (AT) .... well my vac hoses that go to the front diff weren't hooked up so i hooked everything back up and the 4wd worked great ..... i disengaged the 4wd on my way home i noticed that the part time light would come on under acceleration from stop signs didnt think nothing of it... about 2 days later took the jeep out engaged the 4wd and the light didnt turn on ... the 4wd works going thru sand but will not climb any of the small hills that i went over 2 day prior ...... and the part time light still turns on during acceleration ...... all vac line from engine bay to transfer case to front diff are good..... any help ....

 

i am 99.9% sure your vacume is not atached to the front axle this was my problem i was thincking to deep that my t-case needed replacing and so i started to save up when my starter was acting up so i got under the car and saw a cable hanging loose and looked for a place to poke it in to and found the three/two (depending on how you look at it)cables pluged to the passenger side on the front axle then i was likee oh **** my 4x4 works again so i tooking out and did not stop till i high centered best part about it was it was FREEEEE!!!! if this is not pluged in the light will not come up "part time" (that is what will show up)

NOTE this was on my 90 xj unless they changed alot of **** in one year i can get you pictures if you cant find it but it is pretty easy


grandmas like to unplug them because they dont use 4x4 and it is just a bypass to save the tcase

 

I had to replace the vacuum sensor control which had just gotten old with time and wouldn't respond any longer

 

the sensor goes bad alot acording to mine i am always in 4x4 it never goes out but i jaked up the front to see if the hubs were locked and they wernt so i dont look at it any more i can tell by the feel if i am engaged or not