Gang,
I apologize if this has been beaten to death but I can't find the answer int he archives. I have a 2004 Ram with the Infinity stereo. I'm installing an alpine head unit.

Why can't I simply install the stereo without using the expensive adapter? The infinity head unit had connections for four speakers coming out (I believe they were amplified as the unit does have a heatsink on the side). I know the amp behind the glove compartment split up the signal into multiple channels but it seems like it was receiving speaker level signals from the stock infinity head unit. What's different about hooking up the alpine in it's place? If I can't use the speaker levels from the Alpine directly, could I use the Alpine's preamp outputs and hardwire them into the truck's wiring? I'm handy with a soldering iron so it won't be much trouble.

I'm confused.......

 

look for it on crutchfield its like 15$ heres the link http://www.crutchfield.com/p_1207065...e-Harness.html

 

Right, but this is just the wiring harness. Crutchfield recommends a PAC interface to interface with the infinity stock amp

 

depending on when exactly in 2004 your truck was made you could have one of two styles of the infinity system.. The earlier model would use a conventional 12v turn on signal to activate the amplifier and subsequently produce audio... If you have a later model 2004 the factory amplifier is tied into the data system that runs throughout the vehicle and that is what turns it on... Since an aftermarket head unit can't interface to the data/CAN system in your truck (if so equipped) it would need an external adapter.. easiest way to find out is to buy the cheaper harness.. if you don't get any audio after "proper" installation then you need the adapter made by pac or metra or scosche..

the issue is not getting signal into the amplifier it is actually getting the amplifier to physically turn on.

 

Gotcha, it looks like I have the easy way out. The factory harness has an amp turn on lead. I'm going to send speaker level power to the amp and see what happens.

 

If you have the ampturn on lead and hook it up this way will the speakers be running solely on the amp power or will the deck power them as well my deck has 380 watts so has more power than the amp so I want to know if I need to bypass the amp if I want to use deck power?

 

What model head unit are you installing?

 

I hate to even say it but its a xtreme vision xv-4.0 its the only deck I could find that has a 4 inch screen I didnt want a flip out but didnt want to cut the dash to fit a double din. A shop told me to go ahead and wire it normally any clue on how to find out if I have the amp turn on lead like Ben D. was talking about?