[jessicamoores]

When 4x4 is on the axles turn with the wheels so the hubs are good,the front driveshaft is locked so the transfer case is most likely good,i was told there was a pump that built up pressure to lock up the axles in the differential,does anybody know where it is and how to test it,or any suggestions on something else that might be wrong,any help would be awsome,Thanks

 

[stump runner]

I'm sorry, I don't quite follow your trouble shooting you've done. I believe the easiest way to narrow down where the trouble lies is as follows:
1) engage 4wd
2) set the parking brake and jack up 1 front wheel
3) attempt to rotate that wheel
If all is well with the world you will not be able to spin it. If you can, the trouble lies just past the last rotating part. (IE: if the driveshaft spins, the problem is in the transfer case. if the axle shaft is the last rotating part, it may be your front diff or central axle disconnect, if so equipped)

 

[jessicamoores]

ya thats what i did i guess i wasnt specific enough,my bad,4x4 engaged,jacked up front end,both wheels spin with axles and then i checked the drive shaft and it was locked,my 4x4 indicator light comes on, after a little research i learned that the 4x4 indicator light on my dash will only come on if the pump unit builds enough pressure,so i figure i either have a air leak big enough to stop the axles from locking up or the unit in the differential that locks the axles is faulty,(that would suck)im gonna check for leaks in the morning and go from there,thanks

 

[stump runner]

so, is the problem that the light does not come on, or that the wheels do not turn in 4WD?

maybe this thread will be helpful:
2000 chevy tracker front axle question

 

[Bradley Abrams]

I have faced similar issues with my vehicles and have found that keeping the online repair manuals, like those from Do It Yourself (DIY) Repair Manual Online from Haynes , handy has really saved me a lot of time with troubleshooting and repairing my vehicles.

 

[NCLiftedBlazer]

actuator is most likely the culprit. Sometimes, the actuator is good, but the cable is bent, in a bind, or broken. Check out the cable and actuator (hub locker) both should be relatively inexpensive. If there's an electric switch, look into it as well.