Audio Help Needed

[Ark Hoot]

Hi Friends,

I have the 2003 XLT model. It came with the Audiophile cd-6 and has never been molested. My left, front and rear speakers do not work. I changed the left and the right speakers and it proves the speakers are OK. Someone told me that I could hold down the three and the five selection buttons at the same time to make the radio do a "walk around" system check. I did that and it says "speaker short" on the display. This unit also has rear controls with places to plug in head phones. Today I remembered that, so I plugged in a set of phones and the left side is silent.

Here are my questions:

1. Does this unit have an internal amp. I know there is a amp mounted behind the rear seat, but it seems to be only for the sub.? The sub seems to be working fine.

2. What would be the next step in the troubleshooting process?

3. Any suggestions would be appreciated?

 

[Snooze]

Hmm. Its always tricky with factory head units. I don’t know how to trouble shoot them.



Maybe you would be able to take it to a ford shop and they might be able to do a quick switch with another head unit and see if the problem persists. If it does then there is a short somewhere in between the unit and the speakers (which I doubt).



If it works when the unit is switched, then your problem is solved and you know that your head unit might need a little service, or a fuse changed, or something little like that. If its any bigger then a fuse or something, then I would say ditch that head unit and find an aftermarket head unit that you really like.



I always use the opportunity when something fails to buy something new (if the item malfunctioning is too hard to fix).

 

[Mike Franklin]

Having spent my early years at a custom car stereo shop here is what I would suggest. Hopefully, you have a ohm meter. If not, add one to your tool box. In the electronic age, they are just as handy as a set of pliers.



Starting at the speaker, unplug the factory wiring harness from the speaker. Insert the probes from your meter into the harness. Let us know how much resistance the meter reads. Unplug the radio from the harness and again, let us know how much resistance the meter reads.



Nows, with the speaker still unplugged, check the colors of the wires and then go to the back of the radio. Unplug your harness from the radio and put the probes into the slots for that speaker on the harness that plugs into the radio. Let us know how much resistance the meter reads. Now plug your speaker back in, and again, measure the resistance.



Here is what we want to see. When you find the short, it will read zero ohms of resistance. Wether it's in the harness or in the radio or even possibly in the speaker which does happen.



To answer your questions though,



1. Yes your factory head unit does have amplifier circuits built into it. All head units do. These circuits are what drives the door speakers. Thats why your head unit gets hot because the op amp transistors that amplify the signal are heat sinked right inside the radio.



2. See above. Get the info back to us and we can make a determination. Again, the short can be only three places. The head unit, the wiring harness, or the speaker.



3. Lets figure out whats wrong before we take a course of action.





EDIT**** Whoops, I just reread your post and while I was thinking of a factory head unit, the same principles apply for aftermarket head units. Even more so in fact as factory head units can get a little more complicated, Ie, my parents mini van where the logic controls for the airbag is built into the radio. LAME!!!!



As long as your certain that the amp is only powering the sub then everything I typed above should reign true.