Fultec is on Coney Drive.
Coney Drive intersects with Princess Margaret Drive almost in front of the hospital (KHMH). From the roundabout, go past the library (on your left), past the hospital (on your right), and the next left is Coney Drive. Fultec is about 100 or 200 metres from the intersection, on the left side.
There is a map of Belize City on my site. Scroll down to the bottom of the page and click on the map for a larger view.http://belizebus.wordpress.com/
Also, you might want to try GS Com on Baymen Avenue. Do you know where Baymen Ave is? GS-Com is at the intersection with Calle al Mar.http://www.gs-com.bz/