wanted

Just had a boost gauge fitted and used a feed from the lighter for the backlight but when i plugged my snooper back in it went on and then off straight away. I've tried my phone charger aswell and that doesn't work either. Have i tried to take too much power from there with the snooper aswell as the boost gauge. I don't think that can be the case but you never know. Where is the fuse for the lighter so i can check it.
Anyone got any idea what i have done wrong. The boost gauge still works and the ring around the lighter is still lit.