I think the cap on that guys is somehow hooked up wrong and thats whats causing the drain, who knows the cap its self could be bad too.
I was just making another point to mount it as close as possible the amp. I did a quick search online and found this.
"For maximum benefit, you should keep the length of wire between the capacitor and the amplifier to a minimum. Anything (wire, distribution blocks, fuses...) between the capacitor and the amplifier will reduce the capacitor's ability to quickly supply the current needed by the amplifier. Of course, if you have multiple amplifiers and want the capacitor to benefit all of them, you'll have to connect it to the distribution block."
All about caps worth the read

In my case I have two amps one for the subs and one for the surround. I have no intention of making anyone mad just putting my two sence in, and since no one asked the guy in in two pages of posts how he hooked his up I thought I would.