I have a question, it involves car audio.

Basically I have my head unit installed in my car. no aftermarket amplifiers.
I want to enable onstar to work with this system and i have a method figured out. As shown in the diagram....
but my issue is i want to use existing speakers for both systems.
so when the external amp turns on the head unit mutes and allows you to hear the onstar.
but if I use existing speakers would the current from the external amp travel into the head unit and harm it?

If you need further explanation let me know.
Thx

 

A simple representation of what i'm doing..

 

One thing to keep in mind is never to connect outputs of two amplifiers together. The end result is quite smoky if you know what I mean.
You have to use a speaker line level switcher to switch the amps out put.

Rifaa

 

That's what I thought... can you get them as an automatic switch?
ie. when the external amp turns on it automatically switches?

 

Yes , definitely but one has to see what the amp has as a remote terminal
Post the details of all and any connection terminals of the two amps so that I can forward you the necessary details on how you can go about it.

Rifaa