I am installing some VDO gauges. First off my boost and knock are on the pillar and both need power. I bought an "add a fuse" to tap into the fuse box. My question is, can I take and run both power feeds from the knock and boost into one "add a fuse" connector or will they need their own seperate. Also, I see an open slot in my fuse box that is marked "for battery." Can I use this for the power source?