QuestionI installed a Sony XPLOD head unit with a plug to plug into the factory harness. Everything works but I get no sound whatsoever? I have all factory speakers with the exception of an amplified sub that I used line level inputs. Is the plug I bought missing something for the factory amp? I have a 2004 Dodge Ram 1500.
AnswerHi Jeff,
I think you're right in suspecting the factory amplifier; it's very common for the Ram to be equipped with an amp.
Your adapter harness that fits the Chrysler plug should have a blue wire with a white stripe. This is the activation wire for the factory amp; it should match up to a dark green/red wire in the stock radio plug. To activate the amplifier, all you need to do is connect the blue/white wire in the adapter harness to the blue/white wire from the Sony plug.
A few Sony head units do not have a blue/white wire; but in these cases, they don't usually have RCA pre-amp outputs either. Since it sounds like you have your amplified sub connected to the RCA line-level outputs, I'm going to assume that your deck has the blue/white wire. (Is your subwoofer working?)
If you do have the blue/white wire, it's hooked up, and it's in the right position in the adapter harness (matched with the dark green/red factory wire) then I'd use a multimeter to verify that it's producing 12 volts when the head unit is switched on. If that tests okay, then you might want to check your vehicle's fuse box for a factory amplifier fuse. The stock amp typically has its own fuse in one of the fuse boxes, and if it's blown, then you won't get any sound.
Your problem can also be caused by a pinched or shorted speaker wire. You might check the wiring at the back of the deck, to see if any of the wires were pinched when you mounted the head unit, or if you have an uninsulated connection.
Hope this helps!
Brian
