You know, I've barked loudly at other people for this kind of post <img src="/forums/images/graemlins/shame.gif" alt="" /> <img src="/forums/images/graemlins/shame.gif" alt="" />

It was a "dinners on the table" post, and I just shoulda skipped it <img src="/forums/images/graemlins/oink.gif" alt="" />.
I apologise MIGHTY1.

I had a similar problem with my paj last year.

Mr Bishi helped with this:

" sounds like it is an electrical issue.
Most likely the free wheel engage switch either needs replacing or cleaning (bad connection).
This is located next to the actuator rod and if you remove your bashplates can see it clearly. This is the first place to start rather than diving in and replacing the 4x4 ECU behind the dash. Also pays to check the two vacuum solenoids (located just behind the air filter on the wheel tub) to make sure none of the hoses are split or leaking and all connections are good. It only takes a small amount of crap in the wrong place to upset this system so it pays to acquaint yourself with it."

In my case, it was one of the vacuum hoses had come adrift.