Accessory power for head unit?
Melting Slicks
Joined: Mar 2006
Posts: 2,997
Likes: 36
From: Ocean Springs MS
I know I had 3 wires just to the left of the passenger footwell fuse box that weren't connected to anything that I used. I can't remember which one was hot, switched and the ground though. Try doing a search over in the audio section. 
Yup, that is what I used too.
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
You have a couple of options to get an additional switched acc power source
The easiest is to use fuse #22 which is live but not used for any other function. I used an “add a circuit” connector to hook in. This gives you the switched hot.
These are not my pics but show you the hook ups
You can see how the connectors slot into the fuse box/
The other option is to hook up into the spare connector which is available for ancillary devices. I believe this is used for the CD changer so it may not be an option for you if you have one of those fitted.
In the passenger footwell (unless you have a 2004) behind the kick board you’ll see a fuse block and to its left a silver box which is the BCM. There are three wires taped together feeding into a connector.
The Black wire is ground; the Orange wire is powered through fuse #7 but is permanent hot. The Yellow wire is powered through fuse #11 and is switched hot when the key is in the ACC or ON positions. Hook up to the Yellow for switched ACC.
The easiest is to use fuse #22 which is live but not used for any other function. I used an “add a circuit” connector to hook in. This gives you the switched hot.
These are not my pics but show you the hook ups
You can see how the connectors slot into the fuse box/
The other option is to hook up into the spare connector which is available for ancillary devices. I believe this is used for the CD changer so it may not be an option for you if you have one of those fitted.
In the passenger footwell (unless you have a 2004) behind the kick board you’ll see a fuse block and to its left a silver box which is the BCM. There are three wires taped together feeding into a connector.
The Black wire is ground; the Orange wire is powered through fuse #7 but is permanent hot. The Yellow wire is powered through fuse #11 and is switched hot when the key is in the ACC or ON positions. Hook up to the Yellow for switched ACC.
