eGo CTwist LED goes dim with carto attached.

[TheRealYeti]

Like the title. I can get a full charge on my battery, if I depress the button without a carto it lights up the LED like usual. As soon as I screw in the tank, the led will quickly go dim or completely go out. If I stick my ear to the carto it sounds like its working but hardly any vapor get produced. Any idea what is going on? I tried pulling out the center pin on the battery but it didn't seem to do anything. Thank you for your input.