I just finished installing my cda7875 alpine head unit (yea its from 02 and have had it for 5 years) but i had it in my other car. Anyways I finally got a good ground and a good constant 12v source and it powered up fine...but now to my dismay, there is no sound at all coming from the unit. I plugged in my factory deck to check the sound, and it played fine. I double checked all my wiring to the harness..and everything is proper and very secure. So I'm guessing my head unit is broken now? or the harness/ deck wiring is faulty? The unit was working just fine in my other car, so i don't get it?

 

In your other car, was the HU powering the speakers or did you have an amplifier?

 

it was just powering the speakers in my other car

 

My alpine has a feature that shuts off the internal amplifier so it doesn't waste power if you are only using RCA outs. I'd have to scroll thru menus to turn on the "Power IC" if i wanted to use the speaker outs from the deck.

 

take your faceplate off and clean the contacts on both sides, i have an alpine HU that does all sorts of screwy things when the contacts start getting dirty... may or may not help but worth a shot in your case

 

its all good..i got it figured out.... it was the fact that i had a factory amp...so i had to connect the remote turn on directly to the HU itself