subs are pulsing but they still work

i hoop in to my car one day and i turn it on and i hear music from my from tand back speakers but not my rear subs......i pop trunk to see wut the proble is and when i turn back on my radio they start to pulse but they still have min sound also...can anyone help...thanx

i was a little sleepy when i wrote that one above...let me start fresh......................

I have a jvc headunit,2 12" Alpine Type R's DVC2 And A Kicker ZR240 Amp pushin those subs and they are ran at 2ohm.... http://https://www.the12volt.com/ssi/getimage.asp?imgFN=2_2ohm_dvc_2ohm.gif......and i also have an extra battery in my trunk for the subs...my problem is that jus yester day i got in to my car and started it and when i whent to turn up my beats i heard nothing but a loud flutter comming from the subs...so i turned everything off asap...but now it doesnt make a loud flutter,it produces bass but at a minimum with the subs pulseing..can anyone help me out with this??????

That amp's not stable to 2 ohms mono (how you have it).  It's bridgable, but only to 4 ohms.  I suggest upgrading to a class D mono amp that's capable of that load and will give you the power you want.  You can always use the stereo amp to run some front speakers.