I don't have a BT Cruiser but did you verify that the water pump is on (you can check by testing the toilet or shower, etc)? Then, check for shutoff valves for that sink, either at your water manifold if you have one, or in line on the way to the sink (underneath perhaps.
Lastly, sometimes, if the water tank has been empty for a while and recently refilled, sometimes it gets airlocked. What I do in my Tour Master is open the faucet, then open the faucet in the bedroom or shower to clear that airlock and get water flowing again.
Hope this helps and good luck.