No Sound with Aftermarket Head Unit

[JaredJHuffman]

I just installed a perfectly working aftermarket head unit to replace the stock cassette deck in the Premium Sound system. I have all of the Ford shop manuals and matched the wires to fit the new wiring harness. The HU powers up and functions fine (power antenna and all), but no sound comes out of any of the speakers. The speaker wires seem to have signal up to the factory amp, but there is no signal out of the amp as far as I can tell. It seems to me the amp is not turning on. In the thick gray cable with the speaker wires in it, there is an uninsulated wire wrapped in a foil connected to the casing. From the wiring diagrams, I am under the impression that this is the logic mute. I believe this is what turns the amp on, so I connected it to the amp turn on lead, and there is still absolutely no sound from any of the speakers. Has anyone else run into this sort of problem?

 

[NiNeTy Fo SHO]

How did you hook up the aftermarket HU? Did you use the 2nd connector in the dash to bypass the amps? Did you run it through the factory amps?

My first thought would be to unhook the factory amps if you are bypassing them.

 

[JaredJHuffman]

I am using the factory amp, so all I did was match the wires in the dash to connect to the new head unit according to the wiring diagrams.

 

[NiNeTy Fo SHO]

Have you tried unplugging the factory amp? If you are hooking up the wires from the harness of the new HU to the wires going to the amp in the trunk, then it shouldnt work...and probably give no sound as you describe.

Of the 2 connectors you used, do they both look the same except different color or are they different connectors all together?

 

[JaredJHuffman]

Ok, here's where it gets hard to follow for our viewers at home. The original connectors on the car-side (CS from henceforth) are (1.) the small metal-covered plug that is metal shielded on the wire (thick grey wire, which contains all the speaker signals), and the longer black plug that has all the power and intelligent stuff in it. HOWEVER, i cut the end off the smaller grey wire plug, and matched those wires with a different colored longer plug from another Ford car i had. i know for a FACT that those connections are right, other than knowing what to connect the bare wire to that i already spoke about in previous post. From what i have read in posts, and what i have read in the service manual, that wire is basically an amp turn on lead. i have it connected as such, but there still does not seem to be power in the amp. I have done this "double-amping" before in other cars (namely, a Nissan 300zx w/ Bose sound) and it worked fine. I seriously doubt that the factory Ford amp is intelligent enough to figure out that i am sending a speaker level signal to it rather than a line-level signal, so i don't think that is the problem. I could see if the sound was crappy, but it still worked. that would be logical. But the amp just straight up doesnt put out ANY sound? that seems like something else isn't right.

 

[NiNeTy Fo SHO]

This is just my opinion...take it for what you want.

It sounds like your trying to amp an amp. You spliced into the low-level input for your factory amp and provided it with high-level input. Doing this, you can get different reactions depending on the amps. Usually the crappier amp will blow its fuse or just not play.

I was asking about the connector b/c there is a 2nd connector in the dash that goes directly to the speakers. Using this, all you do is unplug the factory amp and your ready to go with no problems whatsoever.

 

[JaredJHuffman]

problem solved. instead of trying to do anything fancy, i just cut the connectors at the amp on both sides, figured out which wires i needed to connect to which, and connected them. works fine. the system is tuned perfectly now, sounds wonderful. the factory amp is no longer even in line. it will be removed from the car tomorrow. thanks for the help!

 

[oh_SHO]

You could have saved a lot of time and hassel if you would have bought the right wiring adapters. Mine cost $8 and all I did was match the wires. Also I believe the amp turn on lead is on the 'power' plug.