what kind of relays do i need?

howie ll wrote: Which is why I made that comment, actually that pompous crap about "undisclosed" location really got to me When your dealing with people like Mr I and myself who install stealthed tracking equipment for a living undisclosed doesn't mean much. Again with the second head unit on all the time via the ACC, you won't need a switch, the diodes are to protect the output stages of both head units from feedback when the other is on Your last suggestion will work fine if you're not powering up any speakers, just line outputs to amps. Otherwise do as you suggested and wait for the feedback to blow up your head units, hence isolating or switching relays.

okay, to clear up the undisclosed blah blah, i just didnt want to go into why i want a second head unit because i see how strict this site is as of topics and where they are posted, also i didnt want to get off topic. but any how, blowing up head units, not okay in my book haha, i see now that there is my way of doing it and there is the right safe way that you know haha. i apologize for my bull-headedness. i see now i came here asking all the wrong questions, so can you tell me everything i will need and how to do it right to avoid any "blowing up" haha so thanks for your much wanted help:)

i am an idiot wrote: Why do you insist on having 2 decks?  Why is preamp out into Aux in not an option?

i want two decks because i recently got a $450 deck for free that has a 7" flip up dvd touch screen and it wont fit in where my other deck is. so i am putting the deck in front of the passengers seat in the dash. and me being kinda ocd i dont want a hole where my deck is now so im leaving it in and obviously because i will die trying to reach for the touch screen. but putting the out into the in is an option, its just kinda an inconvience and i thought, if its possible, why not use relays to switch between which ever one that i wanted to have on. also there is a part of me that thinks this stuff is cool and wanted to use it and say look what i can do haha then i get to explain awesome electronics stuff:)

Not electronics at all it's electromechanical. A) Mr I is as usual quite right, why give yourself all that grief? B) Why not just remove the old and fit the new?

Just to make myself clear as someone who first started installing audio equipment into cars in 1973:- There's no such thing as it won't fit!

the way my dash is the flip screen doesnt have clearance, and thanks for correcting me btw:)

Make a wood and plastic or fibre glass and plastic spaces, dress it the 2"/50mm forward to allow clearance.

howie ll wrote: Make a wood and plastic or fibre glass and plastic spaces, dress it the 2"/50mm forward to allow clearance.

the setup i have now brings the radio out about 2" and it still needs another 2" to clear and then it blocks my air vents and look dumb imo

okay, i guess im stuck doing idiots way since i cant figure out how to do it the way i wanted safely. so i have one more question b4 im on my way. since im just splicing in the main 4 power wires, acc,grd,illum, mem. do i any diode protection anywhere or what? i just wanna do this right at least.

no.