Made one for my own use and it works perfectly. Without the key being inserted the lighter / outlet is OFF - thus any item plugged in will NOT be powered until the ignition key is inserted and turned ON. My wife wanted seat heaters for her 2005 Rocky Mountain Edition / found a set on eBay that fit well and secure. Problem was if she FORGOT to unplugged her battery could be drained since the seat heater was still being powered. She "remembered" for a week then forgot one day only to end up with a drained battery. Found this modification and implemented it - problem resolved. Have materials to make an additional four (4) items / lighter modifications and will sell them for $6.00 each (postage included). Send me a PM for details. HOW IT WORKS - In the fuse panel on the drivers side, locate fuse 3 ( Cigar Lighter) and 21 (Radio). Remove the fuses from these locations and put the in the add-a-circuit. Radio fuse goes on bottom nearest the legs. Insert the add-a-circuit into the radio position in the fuse panel. Take the trimmed blade terminal and stick in the in left side (closest to engine) of the Cigar Lighter fuse location. This will supply the keyed 12V to the cigar lighter. If you want to convert back, just remove the add-a-circuit and replace the fuses into 3 and 21.