Stuck in low

It was -6 celcius this morning when I did a bit of 'shuffling' of stuff about in the yard, as usual, I popped her into low-range (96 2.5 DSE manual) no probs at all, however, pushed the dash button to re-engage 'high' & it just sat there 'flashing'. Appears to somehow be 'stuck' in low, took it around the block a few times to maybe 'shake it down' to changing, but no luck!
Any ideas??

My 95 DT Manual does the reverse of that, it won't go in to low. It has been suggested that it may be the switch on the gearbox/transfer box. Not found it yet to try it out, but mine is not as urgent as yours.

Lenb

Update for anyone who's interested.
Disconnected the ratio motor plug/socket on transfer box, applied 12v to the motor wires & it motored back & forth from low to high ok, obviously I left it in high, so at least I can drive it normaly now.
Removed the gearbox ECU from under the L/H seat, took it apart to find a 'blown' power transistor, took some of the curcuit board with it!!
so now i'm on the lookout for a replacement ECU.

is it easy to remove the ecu, if so go to a lr dealer, test drive one like yours and when you get round the corner, pull up, swap them over, take it back and say, no mate, its not for me