I know this topic has been covered many times, but I have been unable to find a picture or answer to this question.

I have a 2004 F150 FX4 which came with the standard 6 disc radio. I have purchased both an audiophile head unit and subwoofer to upgrade my standard radio. I was able to locate the wire harness under the rear seat which goes to the subwoofer, however I cannot find the 'head unit' end of the wiring harness. It was my understanding from everything I've read that some people have had the 'head unit' end in place, but the wire was not completed to the rear of the truck, however this seems to be the opposite. Can anyone who's done this try to give me a detailed explanation of where I can find the 'head unit' end of the wire or even some photos might help!

I appreciate any help anyone can offer!!

Thank you,
Nick

 

I'm in the same shape as you. I found the end under the seat but I can't find it in the dash.I looked all over in there and don't see anything. The plug under the seat has power with a test light but no sound when I plug in to the sub.

 

I just found mine. I followed the radio wires back and then I saw a grey plug taped on the wires. it was on the left side of the opening wire goes down by a metal brace. It was hard to see because it was behind the brace. Hope you find yours.

 

Thanks for the help! I'll take a look after work.

 

so is it plug n play if we can find the harness in our truck ??? do we need any extra harnesses or plugs/wires???

are the audiophile door speakes different?? i know it has an added tweater....

 

did you find it?

 

hi all, I'm doing the same upgrade both plugs for the sub were somewhat easy to find.
I'm wondering if i will loose the speed volume feature and the bright light for daytime driving? i put a shaker 1000 in and lost both of these functions....
i got a 6d audiophile hu off eBay that say's it will work in 04 to 08 .... ?

 

Sorry to continue such an old post. Ive had some medical issues for awhile that I'm now over with. Anyway--I have searched everywhere for this connector behind the radio!! Im starting to pull my hair out over this!!

Is it possible to have the rear connector that connects to the sub but not the end to connect to the radio?

I did try following the wiring harness that plugs into the radio, all I can see it do is branch off to a ground wire and then to the 'main harness' however I can not find any loose connectors in there.

Thank you for any help! I appreciate it!

Thanks,
Nick

 

Nick,
i think the 2009 year models are different. They switched systems. Good luck.

 

Woops, didnt realize my profile says 2009. The truck I am doing this to is an 04 FX4.

Thanks

 

Nick,

That connector isn't loose from the factory. The harness is sortof folded over itself and connected into a white holder. It will be on the leftside. You should be able to see it with a flashlight and reach in and disconnect it from the holder. If you have the plug under the seat, then you should also have the plug in the dash.

If you still cant find it, try taking some pictures and posting here in the inside part of the dash. Maybe we can spot it for you or confim it isn't there.

good luck,
Bob

 

Below are some photos (not of the greatest angle or quality).

I do have power at the sub connector however I cannot seem to trace the wires past the large gray 'main connector' near the e-brake and hood latch.

 

I have been looking for the sub wires on my truck behind the seat with no luck. Where are the wires suppose to come out for the box? By the door or towards the middle?

Thanks,
Kev

 

If you look under the rear driver seat about half way back on the side closest to the door, you should be able to find an L shaped slit in the carpet. You might have to feel around a bit under the carpet to find it (if you have it). Mine was pretty tough to find, I had to make the slit quite a bit larger to be able to find mine. IIRC the harness was also screwed down to the floor. I just used double sided tape to tape the carpet back down. Cant even tell, especially once you put the sub in!

-Nick

 

I will give it another look at lunch today. Would like to add a sub if the wiring is already there.
Thanks,
Kev