Installed new head unit, +12v Accessory wire not working?

[NeedaE30]

Ok so i tried 3 different used(new to me) decks in my car the past 2 days, the first deck would come on when i hooked up the red +12v accessory wire and turned the key to accessory, unfortunately that deck had a bad rear speaker channel, next deck worked good but was old and ugly, Both of these decks i didnt even need to use the Yellow constant +12v wire and it would work and turn on and off fine with the key, so i got an alpine from a buddy

I ended up having to connect +12v accessory(red) and +12v constant unswitched(yellow) and the cars grey/violet wire all 3 together. This deck DOES NOT come on when i turn the key to accessory i have to manually turn the deck on and connecting all 3 wires was the ONLY way the deck would actually turn on, it turns off when i turn the key off,

so the problem is, the deck does not turn on when key is switched to ignition, the deck isnt saving my settings, and i have to manually turn the deck on everytime i start the car

Is the +12v accessory red wire circuit fried in the deck or did i do something wrong? im confused!!!

[jlevie]

YOu need to move the unswitched (yellow) wire to an unswitched power source. That wire keeps parts of the radio on when main power is switched off. The lack of unswitched power results in the loss of state and settings.

[StereoInstaller1]

Get yourself a $5 testlight and verify that you have voltage on your wires.

Walmart or any auto parts sore should have it.

Don't use a meter, use a testlight.

GL!
Luke