fuses blown

im having trouble installing some cathodes in my ford ranger i tapped in the cigarette lighter for my power source and have a door pin switch but when ever i turn on the lights the fuse for the lighter blows i even put in a 30 amp fuse and it still blows can anyone help me on this or suggest another power source

It's probably grounding out. Where do you have your ground attached?

i first had it grounded with the ground attached to the cigarette lighter but then i switched it to a piece of metal on the passenger side under the dash, should i try the first ground again?

found the problem the stupid door pin switch is a horrible product cause its says on the instructions to put it on the positive wire but when you put it in it touches the frame of the car (negative) making a short
now i just need to find a different place to connect my second set set of cathodes anyone have any suggestions on where to connect them im thinking of having them put behind the seats or in the back window and im trying to make them come on when i have my courtesy lights come on , and i cant connect them to the dome lights cause it makes them dim allot