R51 Pathfinder/D40 navara no 4wd light 4wd not switching

[hgftydtr]

The 4wd in my pathfinder will not switch and there is no diagnostic light on the dash

 

[Old.Tony]

Several factors could be at play.

Try the transfer relays in engine bay. These live in a black box - in my 2009 model, near the battery.

Failing that, check fuses. There's a box (again, in mine) near the ABS unit with a heap of fuses in it, if you can't find the fuse in the first box above. Testing the fuse with a multimeter is NOT sufficient, it must be removed in case the tabs of the fuse have oxidised a little (which will stop power flowing but allow the fuse to test ok).

 

[hgftydtr]

Thanks turns out the issue was the abs sensor in the hubs and the hubs where full of mud