The D-Link 624 is a wireless router so the WAP is built in. BUT your question in the subject may be not what you wanted to ask. I do not see a way to to run wireless router with WAP into just a WAP.
Some try to do this since they have an existing router and didn't know to buy the WAP. My answer may confuse you since I'm answering your question!
My bet is that you haven't updated the FIRMWARE in the D-Link 624 and maybe have not configured it yet. Since D-Link supplied configuration notes, I don't duplicate it here.
Bob
I just got a D-Link 624 router and I'm having a helluva time getting everything working. I guess my main question is whether or not a router can act in the same fashion as a WAP? I want to put my desktop in another room and have the D-Link G520 card for it installed. Obviously, there will be no hard connection between the desktop and the router. Should this work? Right now, I can get the router and card to connect, but once I open a browser to access the net, nothing happens.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic