after market stereo for dodge van

I have a 1996 dodge van with an Infinity sound system. I'm trying to put an after market cd player and I can't seem to get any sound from the speakers. My guess is that I have to by pass the factory booster.If I'm right how do I go about doing this.

no actually you do not need to bypass the factory amp.  The infinity systems in these vehicles use a high level input for the signal, and most aftermarket decks will work just fine with them.  The hookup is basically the same as if the vehicle had a standard factory system, but two things to keep in mind: 1) make sure you hook up the blue (or blue/white, if also present) remote turn on ("system control", "REM", "remote-amp") wire from the aftermarket head unit, to the blue wire in the wiring harness (like the Metra 70-1817), assuming you used a harness.  2)Also sometimes there's a green and black factory wire that's sorta loose back there behind the radio opening, and if it is present it needs to be hooked up to a good ground connection back there--usually the braided grounding strap will work just fine.  This GREEN/ black wire is the ground wire for the infinity amp.