I've got a kenwood kac-8105d amp hooked to the factory radio/nav pushing a 10" pioneer shallow mount sub. It only works if I unplug and replug the high level input connector. I'm using the high level inputs to turn the amp on (I'm using the sub wire and just split the positive and negative to have four speaker inputs) but I've also ran a remote wire to it and that doesn't help either. I'm not new to installing aftermarket stuff but I've never seen this before. Everything is hooked up correctly. Adjusting the sub gain on the factory radio/nav has never helped it to work. I took the amp off and hooked the factory sub back up to test the head unit and it works fine The funny thing is it works about every 20th time I start the ridge and also I've noticed that every now and then when I unlock my doors or open the moonroof it comes on. Another thing to note is once it's on it stays on until I kill the truck. Any info would be appreciated I'm taking the back seat out tomorrow and Moving my sub from under it to behind it and sound deadening the rear floor and wall. I'd rather not have to put a switch on the speaker level inputs or buy another amp. If this is a common problem I apologize I havent been able to find it anywhere.