4WD Front axel will not engage

Trouble shooting why the front axel shift motor will not engage and need a little assistance. My understanding is that the shift motor diaphragm should only recieve a vacuum from either side of the diaphragm, depending if in either 2wd or 4wd. Removing both vacuum lines from the diaphragm thus taking the diaphragm out of the picture I read a equal vacuum reading (10+ in HG) from either line and is this normal? The vacuum switch and both lines are new so I'm sort of stuck as to why I still have readings on both sides regardless of in 2 or 4wd.
2000 Ram 1500, 5.2L  

Have you checked the vacuum switch?  I'm not familiar with the Ram but YJ's use a similar system.  The switch is located on the transfer case.

It should look something like this:

 

So far I checked and verified that the shift lever is in 2WH and that the vacuum plug is correctly seated on the vacuum switch. The switch itself was replaced last Spring when I was correcting a No Vacuum reading on the same system but it was suggested I again replace the switch. Could the Check Valve be a possible culprit?  

Have you tried hooking up the vacuum gun to the line that connects to the engine?  I believe that's the line that has the check valve on it. You want to start testing the lines as well as the components.  So start at one and end work your back to the diaphragm, testing each line.  On a Jeep these lines are hard plastic and can crack over time.  I'm sure they're similar on the Ram.  Although a leak on the check valve side of the line would probably cause a fast idle.  

I have spent time chasing vacuum leaks on a Jeep YJ Dana 30 with this disconnect set up. it is not fun. I finally installed a 4x4 posi lock kit that replaces the vacuum disco with a cable pull. it works very well. I installed one on a Chevy S-10 many years ago and that kit didn't work too great but it was quite some time ago so maybe it's been improved. The YJ kit did work very well though so maybe the Dodge kit they offer will do the trick.


check it out : http://www.4x4posi-lok.com/app_dodge.html