4wd gone Pete tong?

While cleaning and greasing the front brake sliders on the spare Cabrio . I noticed the as I turned a wheel the front prop shaft turned while it was jacked up ..... Engine off ..mmmm that's not right is it?
 The 4wd illuminates and goes out as the lever is operated....and the movement of the lever gives a clunk ...but the clack clack from the hubs dosen't happen .
 It was fine a few weeks ago .
Can it stick in 4wd ?  Turning a wheel and prop turn would indicate hubs engaged ..right? 
I have searched wiki pages but they seem to be about non engagement.  Which makes more sense 

Out of curiosity you could pull the locking hubs off and spin the wheels. It sounds like your locking hubs are just permanently engaged not your overall 4wd.

Your vacuum lines are connected and in the right orientation?

Thanks for input ...the vacuum lines weren't moved so should be correctly orientated .
 At weekend I will release hubs which should unlock a vacuum if that is the case that the hubs are stuck . Curious to know how. It could happen .To be honest I hadn't thought about it not being in 4wd .

It could be that the "disengage" line is broken somewhere, or the "disengage" solenoid valve is stuck.


The "engage" side should be ok if the green light comes on steady.

You could try removing one hub and manually disengaging it, replace it, then engage 4wd (engine running) and see if it pulls in with a click.


The "disengage" side of the system is not monitored .

The solenoid valves have 3 pipe connections
1 goes to the vacuum tank
2 goes to the line to the hubs.
3 goes to fresh air via the filter

When the solenoid valve is off
1 is sealed and 2 & 3 connect

When it is on,  1 & 2 connect applying vacuum to the selected line, the other line is connected to fresh air so air gets in and pushes the hub over towards the vacuum,.

 

Facade thanks for your input, armed with it I searched the wiki further and will endure to investigate at the weekend ..