I recently bought a 2008 F-250 with a simple AM/FM Stereo (8C3T-18K810-AB)

I wanted to have a CD player and an Aux line in for my iPod so I found the single disk version CD/AM/FM Stereo (8C3T-18C869-EB) I also bought the dash panel with the "Line In" 3.5mm audio jack.

I have plugged everything in, and the radio and CD player both work just fine, so I'm now one step ahead of where I was. However, when I press the AUX button on the radio, the display shows "No Aux Audio".

Do I have to have my truck reprogrammed to know that there needs to be a connection between the line in and the stereo? I haven't checked continuity yet, but unless the pickup itself is refusing the connection, I don't see why the stereo doesn't pick up the Aux line.

I'm stumped...TIA.

 

How does the 3.5mm jack connect to the radio? Aux may be part of the CD changer/Sat radio control ports.

 

there is a 4-pin connector that used to be behind the blank dash plate. It now connects to the 3.5mm jack. I believe those 4 wires go to the small radio connection block, but haven't checked continuity yet, only color.

 

4 Pins are one more than needed. A stereo jack has a right, left and common ground.

It is possible that something has to be plugged into jack for the radio to see it. Some amount of resistance so it doesn't read as an open circuit.

 

I also thought 4 wires was peculiar.

Now... does the radio sense the auxiliary port? or does the truck?

Is it possible that my pin blocks just don't match up?

I don't mind splicing a few wires in order to modify the harness so I can use the "built in" 3.5mm Aux jack.

Next time I get a chance, I'll pull everything back apart and put a multimeter on the four wires to see where they go and if there is anything between their ends...like a resistor.

 

Each of the four wires goes straight up to the 16 pin connector on the back of the radio.

The wires are:

Blue w/green trace - mid section
White w/green trace - third section (common)
Yellow w/green trace - third section (common)
Blue - tip section

All four wires go directly (0.6 ohm resistance) up to the radio when the truck is off...so the only two comonents that matter are the "Line In" 3.5mm jack and the Radio Head unit.

It seems the "extra" wire is a second ground. It's possible that jumping these two pins on the head unit is the method of "detection" for an auxiliary port.

I have not been able to find a pin diagram for the 16 pin connector on the 8C3T-18C869-EB radio...but it sure would be nice.

The radio came out of an F-550 if it makes a difference.

 

Or if it senses voltage between either blu or blu/grn and wht/grn or ylw/grn. The output of any audio device to those wires will have AC voltage if it's on, otherwise the radio will think those wires are not connected to anything. Before you go onto too much more, make sure your Ipod/MP3 player/ect have an output, then I would see that that output is making it across the jack to the blue and wht or yellow wires. A dmm on VAC will be handy for that.

 

My DMM doesn't read low enough on VAC for the ipod...200VAC is the finest setting. However, I know that the iPod works. I can plug headphones directly into the 3.5mm jack and get sound. Which means there is a signal. The wires have no resistance from the 4 pin "Line In" connector to the 16 pin radio connector...they are straight through. This leads me to believe that there is a signal going to pins 6, 7, 8, and 14 of the 16 pin connection slot on the radio.

It sure would be nice to get in touch with whoever made the radio...

 

Hopefully 200VAC is just the range, otherwise it's useless for 110v. It should read the 1.5-20v.

Try taping the wires going into the radio with a set of head phones, If it makes to the connector, it's a setting in the radio that must be changed.

 

the ranges on the DMM for AC voltage are 200 and 500. 200 results in voltages accurate to .1v, and 500 results in voltages accurate to .5v.

I was trying to avoid building a 3.5mm jack to rig into the 16 pin block, but doesn't look like that's possible anymore.

There are a few other wires on the 16 pin block that I can't find too much info for. Two of them are labeled as diagnostic high and medium speed. The others are listed as Control Module - radio.

My next guess is that there a module that wasn't installed on the truck since it had AM/FM only. Maybe there is another connector under the dash that needs something to connect to?

Is there any programming that can be done to the radio?

 

You can use some 18ga wire pushed into the back of the connector and then wrap the other end of the wire around a jack, your testing not building a permanent fixture.

.1v AC is close enough to read a signal. I would expect an Ipod to produce atleast a volt at full volume.

I really don't know about programming on that one, I am not very familiar with CAN.

 

My guess is you have to take the truck back to a dealer and have him reprogram the radio to find the aux port. Seems like the 08's have to be reprogrammed for any add on's to work.

 

At the moment, the dealer claims they won't touch it because "it did not roll off of the line like that", and there is nothing that they can do...but I don't believe it.

The local dealer claims that they don't do anything other than swap identical radios if one doesn't work. My next attempt will be to simply state that my "Line In" Aux. doesn't work and ask them to fix it. Then I'll see if they notice that the radio has been swapped.

 

Sounds like you just have a service manager that doesn't want to deal with it. Try to see if you can talk to one of the actual techs, or else try another dealer.

A guy I work with was able to take his 2008 to a dealer and have them turn on keyless entry for him (everything is built into the truck Ford just doesn't enable it on trucks that don't come with the option). I think he said it took the guy about 15 minutes to do it and he gave him $50 cash. You might need to try to set up a similar transaction.

 

Update:

I found the "config" button sequence. Hold Preset 6 and 3 until the speaker test runs, and then press 6 again. This enters the "Radio Config" mode and allows you to see the part number, a number of configurations, and run a "Self Test". Some of the categories are Config 1 - Config 6, PHN, NAV etc.

Now it's just a matter of finding what these numbers and such actually mean. I ran the self test and it responded with "Self Fail", but that really doesn't help much, except maybe it has something to do with the AUX not working. It doesn't seem like I can change anything, but that may be a whole different key sequence.