what should i start to trouble shoot?

 

Please try to elaborate so we can help.

Is this sudden? Slowly losing function?
Does it blow cold air? Does it not blow anything?
Do the buttons light up? Does it make strange noises?
Always a problem? Sometimes?
Did you just change the coolant? Is there air in the system? A leak?

 

Doug< I traded this LR3 for a tile job so I have no idea if it is a sudden. Gave it a lift and put some 06 Range Rover 22" wheels on it. I love this thing.

It blows a very small amount of cool air from the top of the dash towards the window. but the rest of the vents do not work other than some in the rear. and they do blow a little warm air.

The buttons do light up. No strange noises.
I did have the system flushed and new coolant

I was told that they couldn't charge the ac system bc there was a leak. is that the same system? but as I haven't been told that there was leak in the coolant system

 

AC refrigerant and engine coolant are different systems

you should have mentioned you changed the thermostat.. see my reply to your other post

also.. search search search .. many things you will encounter have been addressed here as common issues and you will benefit from years of knowledge

enjoy the ride .. these are very rewarding vehicles if you are willing to put in the effort