Well, I have a 1998 VW Passat that I'm putting a 15" Sundown Sub and a Kenwood 1000W Mono class D amp into. (Also using KnuKonceptz 4 gauge wiring kit if that matters) So anyway, right now I am at the process of setting the amp gain with 60Hz test track and a multimeter (voltmeter) at the number I need (31.6). The problem is, the first time turning the key over in my car after hooking the battery back up with with the amp also, it started and began to idle up and down... this is without the sub or anything else hooked up to the amplifier and before I set anything (set the gain with just they key turned). Therefor, it couldn't have been drawing that many watts to do anything like this right? Checked my grounding, that was fine. Shouldn't be anything having to do with the amp should it? Maybe its just something with my car even though Ive never experienced this before? Anyone know what could be going on? Also, Ill try starting up and driving my car soon to see what it does now.