i would go for the posi lok cable i put one on a 96 worked great way more reliable than a vacume actuator.

 

I put Posi-lock on mine after I hooked to a sled at a truck pull and went 7ft. The best $220 I ever spent.

 

the only thing i know that that tube would be is going into the motor because i've got the same thing and it come out under the hood right next to my air intake

 

That tube is a vent tube for the axle housing!

 

i agree with you blackout94 the cable is the way to go that way its either locked in or its not i put one on my 96 when i had problems getting frontend to lock in the vacum went bad ive had no problems since i put mine in 2years ago

 

then why would it come straight up into the motor where the intake is?

 

the tube goes up so high so that water doesnt find its way into your axle

 

most likely its just like when you check for power at a load if you got power in but the load is not working correctly the load is malf. take the actuator out and hook it up to vac and see if you get any movement

 

hmm never thought about it that way

 

I changed the actuator yesterday, pretty simple, other than the broken bolt. I got it out The e clips were the hardest part It turned out the one vacuum nipple was rusted off and plugged the hole. It's all better now.