Does anyone know of a way to tell if the factory HU has hook-up for factory sub without taking it out? I have an 07 FX4 with the steering wheel controls, 6 disk, 3.5mm aux imput, sirius, and I did find the harness under the back seat. Thanks.

 

I am pretty sure that the stock harness should have the wire, but in order to make it work you will have to crimp into the wire/ I think you will need to get another harness that has RCA's on it so you can hook the sub up to it.

 

ifyou don't have the sub already when you bought the truck best bets you have the reg 6 disc radio. It's been awhile since I used one, I forget what button to use to check for audiophile settings. Look in your owners manual and it will show the audiophile controls. Try them and see. If your looking for stock audiophile I have a head unit and sub available.

 

well i went ahead and ordered a sub thinking i had the right hu and now i am unsure. i went to do the option that the manual says is audiophile only and it wasn't there. guess i will find out for sure when i go to hook up the sub. so smkeater, how much for your hu if i need it?

 

If you have the harness under the back seat, then that harness has to go some place, right? Pull your headunit. It may already be plugged in. If it isnt, follow the two harness' that are already there, and you should find the other end of your further down the line.

 

The audiophile head has a built in crossover. Only highs go to the doors, your current setup would sound like it is missing the lows if you had it.

 

so went to find the harness and i can't. the hu has only 2 harness ports so pretty sure not an audiophile. i followed the main harness and found another head that plugged into an unit that is mounted under my deck which i think is the siruis box. any ideas about where else the harness could be? any one know if you can reuse the existing siruis antenna with an aftermarket? almost sounding easier to install my kenwood in. but don't really want to cause will conflict with plan i had to get my sub and sell my aftermarket. looking for cheapest way from here so wife stays my wife. haha

 

If you found the harness under the back seat, and it is in fact the sub harness, then follow that to the front until you find the other end of the plug. If its in the back, the other end is in there somewhere.

And yes, you should be able to use the stock antenna, however it may take some modification