4x4 wont engage

[BIGTROBINSON]

Ok, help me please. I have a 1997 Dodge Ram 1500 4x4. I had the 4x4 actuator replaced when I bought the truck, Tate Boys said it was out. So I did and it worked fine 3 times during testing and then again during snowy icy weather. I hadn't used it since last winter other than to test it a couple months ago and it worked. I tried two weeks ago and nothing. So I took it to Tate Boys again and they apoligized and said they should have never worked on it, they dont know how to work on vacuum systems but agreed to replace the aftermarket actuator again, and the control switch on the transfer case. Still nothing, won't engage. I've studied and tried everything I know except replacing lines but they all look good to me and Tate Boys. And of course we have like a foot of snow on the ground right now. Any ideas? Thanks in advance

[Tbird100636]

Ok, help me please. I have a 1997 Dodge Ram 1500 4x4. I had the 4x4 actuator replaced when I bought the truck, Tate Boys said it was out. So I did and it worked fine 3 times during testing and then again during snowy icy weather. I hadn't used it since last winter other than to test it a couple months ago and it worked. I tried two weeks ago and nothing. So I took it to Tate Boys again and they apoligized and said they should have never worked on it, they dont know how to work on vacuum systems but agreed to replace the aftermarket actuator again, and the control switch on the transfer case. Still nothing, won't engage. I've studied and tried everything I know except replacing lines but they all look good to me and Tate Boys. And of course we have like a foot of snow on the ground right now. Any ideas? Thanks in advance

:mad:Doesn't know how to work on vacuum system?!? What is that place, a Jiffy Lube type place?!? Make absolutely sure the steel vacuum lines are OK, the vacuum switch connector is connected correctly (should be idiot proof anyways), the actuator hoses are plugged in, and finally, that the vacuum connection at the intake manifold is connected. Let me find the other thread I posted the diagnostic procedure on, it's easy.

[Tbird100636]

Here's one reply I gave recently. I'm looking for the other thread still.

Again, if the vacuum line is disconnected, it won't fully go into 4WD. Basically, the transfer case will be in 4WD, but the front axle will not engage. A test of this is either raise the truck on the lift with the wheels off of the ground, or support the truck on jack stands. Start the truck, put it into 4WD, and put it into drive. If the front driveshaft is spinning the transfer case is working.

You then have to check the vacuum to the shift motor on the RF axle tube. In 4WD there should be vacuum going to both ports. If it isn't check the steel lines on the R frame rail for rot out. Otherwise, the vacuum switch on top of the transfer case is bad. If there is vacuum to the shift motor it is likely bad. A note- the shift motor adaptor bolts have a tendency to snap off. A little heat on the axle tube near the bolts holes helps.

[Tbird100636]

Here it is:

http://www.ramtruckforums.com/forums/showthread.php?t=4459

[BIGTROBINSON]

Well tate boys is like firestone i would have thought they knew what they were doing but i should have researched and just did it my self . The actuator or motor on the front passenger axle is new as well as the vac switch on the transfer case . i will check the lines again tommorow but there are no steel lines the 4 out of the vac switch are just rubber hoses. The two small ones out of the motor are small and are not steel either like thick straws . I will triple check all lines tommorow and are as mad about tate boys as ur . This is the first vac system i have dealt with . I recently installed a cold air intake on it maybe i bumped a connection near the manifold i will check tommorow.