heres what i had planned:

when i hooked the coil wires into the ciggarette lighter i blew the fuse for it up in the engine bay, when i tested it on another relay i had close by putting the wires accross the coil worked fine, relay clicked on with no problems, is it the diode causing the problems? i used this same set up before except on the parking light wire from the rear fuse box and it blew the fuse every time and i figured that was because i wasn't using the ground of the parking light circuit (also why i added the diode)

so my question is what is causing the short? or what other wire can i tap into that will turn off after a period of time once the car is turned off?