Try to make long story short of whats going on havent used 4wd im my 2001 dosge ram 1500 5.9l in 6 years never got around to replacing vacuum lines that were split. Well about a year agoa driving normally started to hear popping when turning and feeling the truck bind kept driving about 20 more miles and dinally it got to point where couldnt drive because of front driveshaft binding. Took off the fronr drive shaft and worked no problems. Few weeks agoa got around to replacing broken vacuum lines by accuator amd t case. Also this whole time the 4x4 lights do not pop up on dash. I pulled the front diff and everything is great in that. When you put it in 4l or h the spindel on the tcase locks and wont spin but you can still spin front tires and front drive shaft spindel. We tested the two wire harnesses coming front 4x4 switch on front axle and heading up back to front of the truck and when we unplug them and use a light tester that is grounded to battery the 4x4 light comes on but when ypu take the tester off light goes right out. I replaced the 4x4 switch it self and still having the same problem any other things i van check?

 

I am having a similar problem. 4X4 indicator never comes on. Actuator works as I can disconnect the wiring harness to the indicator switch and when I put the truck in 4WD the switch goes to 0 ohms, when in 2WD it reads open. I checked for voltage on the wire but have none. Is there a fuse in line somewhere? Where does this voltage come from and should it be 12 VDC?

 

Have a look here.

 

I did not see a fuse but it seems that it must be an electrical issue somewhere in the two harnesses because when i get a wire and jump power to the 4x4 switch on the accuator the light comes on too

 

Verify you actually get vacuum in the right places at the CAD actuator. The metal lines like to rust out....

 

Thats my next plan im waiting on a friend who has a vacuum tester. And im new to this area so i really dont know but is there a way if thay shift motor is bad that is wont finish the connection cause it appears the 4x4 switch touches that for power ?? And also if i remove accuator to look around in there and at shift motor how much gear oil would i loose? Thanks for feedback

 

Lots of possibilities there.... Don't really need a vacuum tester. Just start the engine, and put your finger over one of the holes. If there is vacuum, you should feel it.