2003- 2008 - Front 12V Power Socket Rewire

Looks like the easiest way to convert the front accessory... 12V outlet to constant, unswitched power would be source a new +12V power supply. This new 12V power supply should be fused & attached to [1] where the YB - yellow-black wire is connected. For a light load, you could source this new 12V power supply from under the dash... say fuse #19 in the cabin fuse box with a fuse tap. For a higher current draw, a run directly to the battery would be the way to go.

Again for safety, any sourced +12V power supply should be fused

Bobby...


['07 FSXT Member Journal] ['03 X Member Journal]

Yeah I figured the front (dash) socket would be challenge. I don't like the idea of the seat heater relay being on the same circuit. It would be way too easy to leave the heaters switched on and they would eat a battery in minutes.

As a side note, I notice the TCM (transmission control module) is also on the same circuit as the dash socket. This is strange as it means that while driving I could inadvertently overload the front power socket causing the transmission would mess up!

So, as I figured, it seems the best option for the front socket is run a new fused circuit to the battery. I was hoping someone had done this and has some insight into what needs to be taken apart to run the wire. If I do it, I'll have to make sure I take pictures and post it here for others.

@2.5x_sleeper , thanks for your guidance on how to tackle the center console and rear sockets. For some reason those links you sent didn't work but I'm pretty sure I ran across them earlier. If I remember right, one of them involved a red jumper that somehow had the perfect relay connectors on each end.

I'd like both the sockets up front to have direct connections with the battery so that while camping I can draw power from one port and charge the battery (or at least mitigate battery drain) with a portable solar panel though the other. My rear outlet in the hatch is often hard to get at with all the gear I stuff back there. The dash would often be the best spot to connect a solar panel as I could set it on top of the dash under the windshield.

I was just about to cut the YB wire that serves the dash socket at the the cabin fuse box and splice it to the jumper I'm putting on the rear accessory relay connector. They are right next to each other. Basically the same as a fuse tap. But if there is a way to do it without cutting harness wires off connectors I'd rather go that route. So I removed the cabin fuse box and was going to open it up and see if I can do the rewiring internally to be more clean. Has anyone had any luck getting these open? It looks like its designed to split open like a clamshell with all the wiring attached to only one half.

I would not disassemble that fuse box... way too many things could go wrong!

My recommendation was to "lift" the wire off the back of the 12V outlet being modified for constant, unswitched power. Spare out that wire. Then source a "new 12V source", via a fuse tap, on fuse #19, which is constant, unswitched power. Fuse #19 provides power to the other... console & cargo area 12V outlets & is fused at 15A.

I attached my marked picture of a fuse tap below.
The fuse tap can be inserted either way, so verify that you have +12V on the non-load... common side for the fuses to be configured correctly. The easiest way to verify this is to test the fuse socket being tapped. Remove the fuse & probe for +12V. Once +12V is found, the common side of the fuse tap plugs in there.

Bobby...


['07 FSXT Member Journal] ['03 X Member Journal]

Completed. I ended up powering all three sockets through the original 15 amp rear accessory circuit (F/B cabin fuse 19). I first removed the trim around the front dash socket and under the steering wheel:

The trim piece around the dash socket easily pries up from the back side near the cupholders. To most easily get this piece off, the shifter should be in the neutral postition (with the parking brake engaged of course).

I then snipped the ACC switched yellow wire a few inches away from the dash socket connector. Then I ran a new wire between this area and the rear accessory relay which is located to the left of the cabin fuse box. There are two relays attached to the left side of the metal fuse box support. The rear accessory relay is the bottom of these two relays. I made sure to route the wire so it doesn't interfere with the movement of the adjustable steering column.

I didn't use the fuse tap method because I could not find one rated for more than 10 amps in any of the local stores I tried. But I now see its easy to find higher rated ones online.

Now if I accidentally leave my phone in my car at least it will be charged when I get back :smile2: