hello i have a 4x4 well right now 2wd 1994 dodge 1500. i was wondering if any one has a clue on it being the acutator or if the vacuum lines could be messed up......there are two lines that plug into it and they are red and black. the black always has suction in 2 hi and 4hi. any help would be much appreciated. thanks

 

If the vacuum doesn't switch when you shift the t-case from 2 to 4, switch on the t-case isn't working. Replace it.

 

you must have vac on the proper line at the proper time, then step through it one step at a time. it can fail for any of about 4-5 reasons. broken vac line is most common, sticky/rusty shaft inside the CAD is second.

put it up on 4 jack stands to test.

http://dodgeram.org/tech/repair/4X4/4x4_engagment.htm

 

the red wire has no vacuum at all, but when i hook up a vacuum pump the 4x4 still will not engage, not sure if that would narrow it down

 

Go to FAQ/DIY section on the main page here and download the FSM. Print out the section on CAD operation and carry it out with you. Find the switch that dhvaughn mentioned and start there.

 

work it one step at a time.

if the red line has NO vac in either 2wd or 4wd, then you must fix that. vac on one line is required to engage the fork. vac on the other is required to disengage.

you can dummy the vac with a pump and that leads you to your second problem, cad diaphragm (and fork) not moving. stuck shaft.

after you work on it a couple of times and get tired of it, get a posilok cable and ditch the vacuum.

 

oops, wrong thread.

 

I found a whole in in my line and it was clogged got that fixed but still been to lazy to check the actuator to see if it's working I'm thinking it might be clogged sense the line was clogged