Did you charge the cap slowly? I have a cap that came with a resistor to charge it slowly and another came with a light bulb, same idea.
A 3 F cap takes a huge in-rush of current to charge it, but only for a millisecond. Yup, it will blow fuses.
I've also hear of caps being installed in series.. that really f...s things up.

I'm wondering how your system is hooked up? when you say you blew 3 40 amp fuses?
Is one on each amp? But didn't you say you had 2 amps? so wheres the 3rd fuse? Is there a bigger fuse on your 0 gage?

 

I think the amp has 3 40a fuses!

 

I charged the cap slowly with the light bulb and its wired same way i have wired every other cap ive installed. Its goes battery to distro/distro to cap +/cap + to amp + and then the cap has its own ground and the amp has its own ground.

And yes my dclass md2 has 3 40a fuses. And i have a 250anl at the battery, and a smaller 100anl on my 4g after the distro.

Kyle.