Configure one wireless access point

I have cable modem broadband entering my home and is wired to the various rooms. The modem is a also a router and wireless access point. It delivers a signal via Ethernet to a room on the far side of the house, and I installed an Intellinet Wireless access point there (because the main wireless signal is too weak there). The access point is functioning, but at a speed the fraction of what is delivered to the Ethernet port there, and the light on the modem is orange rather than green (if I connect a laptop to that jack in the far room, its green with full speed, so I know the signal is good). I believe the wireless access point just needs to be properly configured. I can screen share the interface for someone to help me configure it properly.