Low/high range selector spinning

[SimonI]

I have just bought a 2008 GXL 200 Series 4.5 twin turbo V8 love it but the selector that changes the vehicle into low range does not work nor does the DAC button. I am assuming they don't as no lights come on the dash to indicate the vehicle is in either of these modes? Wondering if this is an expensive fix?

[Woodduck5]

Sorry to ask the obvious - you are stationary and in neutral.  Then turn the switch and wait at least 10-15 seconds.  The light should come on (4LO), you will feel the clunk and it will have engaged.  When you put it gear (D or S), you'll know the difference immediately.

If the 4LO light is flashing - engage gear and then back to neutral and it might engage - bout you'll probably have to start the process again.

If that is what you are doing (and it isn't engaging)  - yep, you have a problem.  If can access a Scan gauge or Ultra gauge, they might be able to show a trouble code and that will assist to diagnose the problem.