[H3 Hummer 64]

So I hook up a pair of 520s about a week ago. I tapped into the brown wire that goes into the 12 pin connector on the back of the HVAC controls for power to the switch. This was recomended by Fstop in another thread. Everything works great. Now I got the factory switch to replace the PIAA switch and when I hook that up it blows the fuse everytime. The fuse for the HVAC controls is only a 10 amp fuse. If I put the PIAA switch back on it works fine. So how do I fix this? Can I put a larger fuse in its place? Do I have to find another 12 volt power source? Please help.