From the addon descriptions:
Code:
displays (already discovered) harvest nodes and chests on map, compass and in the 3d world
Did you try to pickup any chest/ore/wood and is a marker shown on your map afterwards?
Did you enable the HarvestMap zone addon parts (HarvestMap DC zones, etc.)in te addons section? There were (not sure if there are still) some sub-addon parts that you need to enable if you want to see pre-defined harvest nodes on your map.
Check the addon description there is a FAQ too.