Can anyone tell me what the nonterminated bundle of four wires (red, white, blue, and black), located under the hood, on top of the engine compartment, directly in front of the steering wheel, could be used for on my my 2006 F250? I am hoping that they may be used for the addition of switched fog lights. Thanks.

 

Welcome to FTE!
Y'up! They can be used for whatever you want to use them for. Why Ford opted to give us those pass-thru wires I'll never know, but they are useful little buggers. Maybe they thought we'd screw the firewall up if we tried to pass wires through ourselves.

 

EnviroCon,

Hi! I thought i'd ask the question, i tried to use one of these wires to run power to a pair of fog lights, and what i got was nothing, although i hooked a wire to the Orange/lt green wire (Aux#1 lead) and then to the white wire. What's weird, i tested the jumper wire before connecting to the white wire through the firewall, and i got power, but when i hooked the jumper wire to the white wire and tested on the firewall side, i got no power.
Ever run into this? And before you ask, i even hooked up to the red, blue and black, and all the same, no power on the engine side, although i have power on the pedal side.

Any suggestions?

 

Hopefully you tested the wires using a multi-meter and not a circuit tester. It's unlikely (but not impossible) that all 4 of the pass-thru wires are cut. So, if you were using a multi-meter, it's possible that you just used a bad ground in the engine compartment and that's why the meter showed no voltage. It's also possible that when you were hooking-up the live wire you managed to ground it and blew the fuse (if I only had a dime for every time I ignored the "disconnect the battery" rule and did that. . .). And the 3rd possibility, and no offense on this one, it just pays to cover our bases and everyone makes an oops from time to time. You simply turned off the power and forgot to turn it back on when you tested the wire again. So I would check the wires again. Starting with the live wire to make sure it still has juice. Then get a length of wire long enough to hook it to the battery and the end of the white pass-thru wire (or whichever wire you want to use) and test to see if you're getting voltage inside the cab. Make sure you test the meter's ground first by testing a known live wire. Just make sure that when you hook-up the wires, and you're running back and forth from the engine to the cab they don't ground out on anything either inside the cab or where you twisted it together in the engine compartment. If you still don't get power going thru the wires. . .Screw-it. You've wasted to much time already and it would probably be easier to just run your own wire through the firewall. Let me know what you find-out.

 

If I'm not mistaken, aren't those pass thru wires NOT hooked to anything under the dash. They are just that...pass thru wires, no power on 'em.. You have to hook 'em up to where you want them to go...like to one of the upfitter switches????

 

Yes. He had it hooked-up to Aux 1.


islandman63- I missed a 4th option. The jumper wire came loose on one end and wasn't getting a good connection with either the live Aux. wire or the white pass-thru wire.

 

Okay, i've found my problem, it was in fact a bad ground, although i was grounded (per se) to the frame on the hood, i must not have had a good ground. Because when i went straight to the (-) side of the battery, and tested the wire, i had power. So all is good now.

Thanks so much for asking the "simple" questions, that made debugging easier on my end. I sure would have thought it was a waste of good effort to put the pass through wires there and have no connection, whew!

 

Those wires are there to be hooked up to an upfitter switch box.
instructions can be found here..
http://members.***.net/richardray/Up..._Switches.html

 

Glad to hear it was something simple.


Just to remove any gray areas and not to be argumentative. Those wire's are not there solely for the purpose of hooking up to the upfitter switches. They're convenient for that purpose if you'd like. They're "customer defined" wires. Meaning you can use them for anything you'd like (as long as the current doesn't exceed the gauge). Ford's been putting those wires in the SD long before they put in the upfitter switches in '05. I used 2 of the ones in my '04 to hook-up my TruSpeed.

 

Ford puts the wires there for customer convience, may it be a consumer , or a upfitter, they are thier to keep installs simple.

 

There is alos a 5th wire coming off the fuse box labeled Customer access, 10 amp fuse for your use as well. Wire hangs up behind where the up fitter switches are as well.

All kinds of options . . .

 

Thamks for the quick replies. Now if I can just figure out how to wire the foglights into the lowbeam circuit...

 

Thanks for the quick replies. Now if I can just figure out how to wire the foglights into the lowbeam circuit...

 

What exactly is it you want the low-beam circuit to do? Do you want the foglights to always come on with the low-beams? Or do you just want the foglights to only be able to be turned on when the low-beams are on?

 

I need the foglights to only be operational while the lowbeams are on.