Stereo Install: Black wire on fuse panel is OK?

[DJ_Allatoona]

Upgraded the old/cheap (Dual) in-dash stereo with a new gauge-style unit with Bluetooth and USB ports, etc. My '75 Starcraft SuperSport has a fuse panel similar to this: http://www.whalercentral.com/forum/attachments/fuse_block.jpg

I connected the red lead to the top of a vacant fuse, but instead of running the black wire to the battery or grounding it on some metal piece, I attached it to a screw beneath the fuse. Stereo works! But is it OK to leave it like that permanently?

Also: the old stereo used a 2A fuse, but this new one blew the fuse, and I only had 2As with me. A replacement 2A fuse is holding on so far, but I read somewhere that this unit likes a 10A fuse. How would I find out which fuse to use?
Thanks

 

[Scott Danforth]

assuming the terminal below is a grounding terminal, and that you have a large enough wire feeding the fuse panel/terminal strip you should be fine.

 

[StingrayMike]

To find out which fuse to use, sometimes it says it on the radio, either top on bottom, or just google the model and look up the specs.
if it ues a 10amp fuse, 2 amps would blow. for your radio protection, better fnd out which is the proper size.

 

[Bondo]

but instead of running the black wire to the battery or grounding it on some metal piece, I attached it to a screw beneath the fuse.

Ayuh,.... Is this screw is groundin' the stereo through the hull, If so, yer hull will begin to rot away,....

The ground needs to run through wires to the battery ground,...

Pick a ground wire that's already under the dash,....