Project: switch to choose which power supply for stereo

[DJ_Allatoona]

'75 Starcraft SuperSport. I recently upgraded an old crappy radio to a killer stereo head unit with BT, USB, etc plus new speakers. It's awesome and I want to run it when I'm stopped. I have a portable/rechargeable 12v power supply with cigarette lighter plug that I used to run my Sirius radio with, Now I want to be able to switch between the fuse block and the portable power with a dash-mounted switch. I think a PERKO-type switch is overkill, since the switching would be after the fuse block. Plus, those damn things are expensive!

Would it be safe/practical to use a simple 3-position toggle switch, similar to this one?
http://www.amazon.com/DPDT--OFF--Po...70995&sr=8-10&keywords=boat+switch+3-position

 

[lmuss53]

A switch like that will work, just make sure it will carry all the current the stereo draws and then some.

 

[alldodge]

Would it be safe/practical to use a simple 3-position toggle switch, similar to this one?

Only if your radio does not use more then 10amps, and does not use an external amplifier

 

[gm280]

DJ, like ALLDodge said, that switch will work if you don't exceed the current handling capacity. And that would be around 15 amps at the lower voltage you are using. However, IF you need more current then any typical toggle or rocker switch can handle, you can use a general replacement auto relay that can easily handle 30 amps or more. It is all in what you need.