i just today got my discovery back from the land rover dealer after having the head gaskets replaced. they had to reset the truck for some reason, and i had to reset everything. on the way home i noticed even at the "LO" setting, i couldent get the air con to kick in, it was reading 76 degreese outside. is this somtime that i can switch quick?, or is it back to the lr dealer. (it was there for 8 days, i live 50 miles away).

 

Take it back make them fix it and wash it for free.
They probally disconnected the A/C and forgot to re-fill it with R-134.
It's happened before.