I have attempted to install a sub and amp in my 2008 250 SD. Got it in and working but I need a remote turn on source for the amp in the front passengers side floor fuse box. The "radio" fuse is a constant on circuit. I need something that will shut off it's killing my battery and I'm pulling my hair out I have tried a dozen different fuses with a test light but can't find one that has power when it's supposed to and none when it's not. Any ideas?

 

Welcome to FTE

You need to get a copy of the wiring diagram for your year.
Look for the accessory delay relay line. It should also be in
the plug in the back of the head unit (well maybe).
I found this. Take a look there is an amp wire in the list.
2008 Ford F250 Stereo Wire Harness Color Codes
2008 Ford F250 Stereo Wire Harness Color Codes
Car Radio Battery Constant 12v+ Wire: White/Red
Car Radio Accessory Switched 12v+ Wire: Blue
Car Radio Ground Wire: Black/Blue
Car Radio Illumination Wire: Violet/Gray
Car Stereo Dimmer Wire: N/A
Car Stereo Antenna Trigger Wire: N/A
Car Stereo Amp Trigger Wire: Violet/Red
Car Stereo Amplifier Location: N/A
Car Audio Front Speakers Size: N/A
Car Audio Front Speakers Location: N/A
Left Front Speaker Positive Wire (+): White
Left Front Speaker Negative Wire (-): White/Brown
Right Front Speaker Positive Wire (+): White/Violet
Right Front Speaker Negative Wire (-): White/Orange
Car Audio Rear Speakers Size: N/A
Car Audio Rear Speakers Location: N/A
Left Rear Speaker Positive Wire (+): White/Green
Left Rear Speaker Negative Wire (-): Brown/Yellow
Right Rear Speaker Positive Wire (+): Brown/White
Right Rear Speaker Negative Wire (-): Brown/Blue
Car radio wire color information above is updated as
it is submitted by the Modified Life community.


Sean

NOTE : One more place to look http://www.the12volt.com/installbay/...asp~TID~102045

 

Often the "remote" wire comes from the radio itself, generally blue.

This only applies to aftermarket radios, but that's where I would start. The remote is just a signal to then the amp on. It will always been in standby sucking very little juice vie the main power cable, looking for that signal to turn on. Small gauge wire is acceptable for the remote signal.

 

This is exactly right. Occasionally, one may find it as a blue cable with white stripe on it. Again, this is only for aftermarket units, but I am thinking that if you are installing aftermarket subs and amps, you may have an aftermarket head units as well. In any case, check the wiring diagrams for the "amplifier remote".

If it is a factory unit that does not have pre-outs, you might need to wire it to a switch of some sort...I can't think of another wire under the dash that would act as this "remote"

 

I appreciate the help! I am using the stock head unit for now but I am wiring everything to go behind the head unit for ease of install if I decide to get an aftermarket radio. I will check for the amp wire behind my stock unit. Thanks!

 

You will find your subs and even your stock speakers will sound MUCH better with an aftermarket HU. If is a night and day difference.

 

BTW Please keep us updated and if you think about it and
hace the time please post photos.

Sean