I have a 1996 Dodge Ram 1500 pickup with the Infiniti Speaker package. A couple years ago I replaced the Head Unit so I could get my iPod to hook up to it. It worked great for a couple of years. Then I started getting some uncontrollable popping going on and I would then shut the radio off. Now I only get audio out of the driver's side door and rear, nothing out of the Passenger side door or rear. Is there another amplifier in line somewhere? I saw someone said it was on the speaker in the door, but that looks like a crossover to me to separate the bass and the treble between the 2 speakers in the door.

I have some 6x9's I can replace the door speaker with, but the speaker behind the passenger seat not working is baffling to me.

 

I would check and see if they are getting a signal at the speakers, the two center wires of the connecters are the signal wires, if they are it could be blown speakers if not make sure there still connected to back of headunit and if so check signal from the headunit

When you swap out the speakers ditch the amp