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12 vlt acc source under hood of 2004 Expedition

BraveSirRobbin

Moderator
I have a 2004 Ford Expedition and I need to find an Accessory source (12 volts only when car is running) under the hood via any wiring location.

I'm needing this so I can install my X-10 Car Monitor behind the front grill.

I placed THIS post in "The 12 Volt" forum, but it's either to complicated a question for that forum (doubt that), or they just don't care to help out some "rookie" they don't know (geez, glad we aren't like that here :eek: ).

Soooo I'm asking our versatile membership if they may know the answer (or at least point me to a place that might). I found the color code for the "wiring harness" but I'm just not sure which one they mean. I really don't feel like "pricking" wires with a meter (wife's car) unless it's the last resort!

Also, showing my ignorance for car electronics/wiring but are the color codes established for the entire vehicle? In other words would a color in one harness represent the same voltage/function as the color in another?

Thanks

BSR
 

pete

Active Member
. . . the best I/ve come up with for this type of 'hack' is to find the fuse box (many newer cars have 2, 1 under the dash, 1 under the hood) . . . poke around there with your meter till you find a circuit that suits your needs . . .

. . . I also prefer the 'squeeze on' wire taps . . . like those picture here, they can be had a your local radio shack or auto parts store . . .

for car electronics/wiring but are the color codes established for the entire vehicle? In other words would a color in one harness represent the same voltage/function as the color in another?
. . . not in my experience . . .



Pete C
 

Skibum

Senior Member
If you have to go to the fuse panel use a FuseTap. Never force anything into the socket.

123514.jpg


What kind of monitor? What is the current draw?

Also, showing my ignorance for car electronics/wiring but are the color codes established for the entire vehicle? In other words would a color in one harness represent the same voltage/function as the color in another?

No. And don't even THINK of poking around with a test light! All testing needs to be done with a meter or specially designed test indicator.
 

Skibum

Senior Member
I've owned a radio store for 15 years... :)
I used to do a lot of 12 volt stuff. Now only a bit. Too busy answering e-mails! :eek:
 

electron

Administrator
Staff member
The fusetap would probably be the easiest way to go, or you are going to have to run a wire from inside the truck, through your firewall, into the engine bay, which isn't fun (I ran into these problems when installing my CarPC) :eek:
 

BraveSirRobbin

Moderator
Thanks for all the replies so far. Ski, excellent idea with that fuse tap.

The problem is there is no fuse box under the hood. The large fuse box is inside behind the "kick panel" where the front passenger places their feet (to the right).

That panel has spare fuses and also some accessory labeling in their manual. I can't believe that a major car company would NOT have an accessory outlet that is easily available. My son's Saturn has an easy to get to fuse box underneath the hood with everything easy to get to and clearly labeled.

The problem with using the fuse tap would be getting that wire underneath the hood (as electron described). There is so much stuff going to that firewall on both sides that I would be scared to death drilling a hole through it!

I was hoping that one of those many wires from all those harnesses (under the hood) would at least have an accessory voltage available.

Also, I do all my probing with a modern day "Fluke" autoscaling multimeter. Do not use a light bulb to test for voltages as I believe if you get on one that is connected to an airbag, you could accidently deploy it (which is why I don't want to just start probing wires in those harnesses).

I may just take this down to an alarm/stereo installer and ask them.

Also, TonyNo, I couldn't get that link to pull up for me, but I will investigate further.

Kinda funny that I'm getting a lot more replies to this problem than over at "the 12 volt" forum! :eek:
 

electron

Administrator
Staff member
You probably wouldn't have to drill a hole in the firewall, I used the steering column gasket, but there are usually several available holes (look for grommets).

My Taurus has a fuse box in the engine bay , and in the location you just mentioned, I would be really surprised if you don't have any fuse boxes in the engine bay at all. Check the owners manual for the location of the fuse boxes. I'll check my sources to see if I can get a wiring diagram. I have a technician CD for the 2001 cars, but the Expedition has been redesigned since then.
 

Steve

Senior Member
I am by no means an expert at this but once when I had to run a wire through the firewall I did the following... The steering column had a linkage that went through the firewall and the linkage was surrounded by something like a large rubber grommet. I poked through the grommet with an awl and pushed the wire through that. It was a very tight fit which I thought was a good seal. Anyway, don't know if that was real kosher or not but its what I did and I've had no problem with it. But anything like that may void your warranty too. Good luck.
 

TonyNo

Active Member
The link I posted is the staring point. On the left should be a list of manufacturers. Start clicking there. You'll end up with a nice table of designations, wire colors, and locations.
 

BraveSirRobbin

Moderator
Yea, there are a ton of ways to do this, but I'm sure this information exists somewhere so it is painless. I mean, what do installers do if they need to install an automatic starter or car alarm?

This info HAS to exist somewhere!
 

BraveSirRobbin

Moderator
Tony;

Here is the info I got off of your link you provided. Is the ignition harness on the steering column?

Can I somehow trace the ignition harness to a location under the hood?

Do I use the one circled?

Thanks again for all the help!

BSR
 

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electron

Administrator
Staff member
They would use the wiring diagram, not much else is needed. I didn't see the link Tonyno posted until just now, it should give you all the info you need.
 
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