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My RS does have C431 on it, but only 2 wires, for the Intelligent Access antenna at the back of the car. Tag on the harness that goes onto the bumper is G1ET-15K868. But to get a really OE look you could by the pins and right gauge/color wires and run them though C431.

Or, maybe buy the Euro rear bumper harness and just remove the parts for the parking sensors, that would give you the plug for the rear fog too. Then you just need to go from BCM to C431 and C431 to ground.
 
Discussion starter · #22 ·
@ControlNode thanks for another great bit of info!

Since I didnt buy the OE rear fog I’ll have to wire a connector anyways at the rear fog so I wont bother replacing the bumper harness but I’ll sure make my harness as stock looking as I can! Didnt really expect the wires to make it all the way to the bumper but at least now we know!!

I’ll try to confirm if there is an actuak wire in the harness connecting at the BCM over the week-end, and then figure out where it ends if it’s actually there!

Thanks again!
 
At this point I doubt you'll find a wire in pin 10 of C2280B, the wiring diagram show that as a direct connection to pin 9 of C431 and only pins 11 and 12 of C431 have a wire to them from the chassis side of the harness. My guess without looking at that BCM plug is that you'll likely be pulling the right interior apart if plan to route it with the chassis harness as it would go. I'm not sure the part numbers for the pins, but I can say the book shows 20 gauge wire. But if you get the right pins (1 for C2280 and 2 pairs of male/female for C431) to insert into the plugs it should not be hard: One power wire from BCM to LED through C431 and a ground wire from LED to ground point (looks to be near right tail light) again through C431.

But, if there happens to be a wire from pin 10 of C2280B, look around near the rear junction box for a 2 pin plug not connected to anything (C436), that may be there to support a left taillight fog light and is from the same pin on the BCM. If that exist may just need to run a wire from C436-p2 in the left rear area of the car to C431-p9 on the right rear area of the car.
 
Discussion starter · #24 · (Edited)
At this point I doubt you'll find a wire in pin 10 of C2280B, the wiring diagram show that as a direct connection to pin 9 of C431 and only pins 11 and 12 of C431 have a wire to them from the chassis side of the harness. My guess without looking at that BCM plug is that you'll likely be pulling the right interior apart if plan to route it with the chassis harness as it would go. I'm not sure the part numbers for the pins, but I can say the book shows 20 gauge wire. But if you get the right pins (1 for C2280 and 2 pairs of male/female for C431) to insert into the plugs it should not be hard: One power wire from BCM to LED through C431 and a ground wire from LED to ground point (looks to be near right tail light) again through C431.

But, if there happens to be a wire from pin 10 of C2280B, look around near the rear junction box for a 2 pin plug not connected to anything (C436), that may be there to support a left taillight fog light and is from the same pin on the BCM. If that exist may just need to run a wire from C436-p2 in the left rear area of the car to C431-p9 on the right rear area of the car.
Yup no wire at pin 10 (see attached picture with red retainer taken off to look at the pins). 1 is at the top right!

Luckily I went to my local scrapyard this morning and pulled a spare connector of a 2013 focus.

I pulled it apart and now have 27 wire pulled out of it with the pins! Plus now I know how to proceed with adding a pin without breaking anything on my car! Will choose one of the bigger gauge wires and insert at pin 10 see if I can get a signal for the rear fog! Might need to pull the glovebox out cause there is little to no slack on that top connector (also practiced that on the scrapped car)!!

Will post details on how to pull connector apart and add pin when I am on my computer. It’s pretty easy actually!

If it works I’ll also have lots of spares wires with pins I can give away for free!
 

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Discussion starter · #25 ·
Added a wire at pin 10. Thought it worked for a second BUT that’s just because I first tested it with the fog turned on..was excited to see the voltage show on my multimeter until I turned it off and still had voltage.

So it’s putting out 10.XX volts all the time no matter what I switch On/Off.

Could there be some Forscan programming required, like the Fusion/Mondeo guys did?

I guess next thing is retrieving the asbuilt data from a euro RS and comparing with mine, starting with comparing the lines found on other platforms!

Unless more wiring or wiring to a different pin is required on our NA RS. @ControlNode if your wiring manual is showing those wires could it be applicable to the Euro RS only and ours would be different in some ways like the rear fog output from the BCM? I’m done for today but will look further into it later this week. Thanks again for your help identifying the fog wires!
 

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The book appears to have multiple markets info in it, I know it is for my car though as it has Sync3 info, NA was only market with that in 2016. But in the same logic it list non-Sync3 info, and we know all of NA RS came with Sync3 only.

This info is more of test at owe risk: The wiring for the rear fog does not show these pins as related, but looking at the C2280B connector view there are several pins in addition to 10(RD-BK) that show that same Circuit ID (CLS45) and list (FOG LIGHT REAR +) as the function. Pins 9(WH-GN), 12(VT-GN) and 13(VT-GN).
 
Discussion starter · #27 · (Edited)
I’ll check pins 9, 12 and 13 next time I feel like bending under the dash panel! Thanks again for the wiring tips!

Probably wont be this week as I’m going ice racing on friday so I need to prepare for that! Last chance for making it work without looking into Forscan I guess.

I feel I’ll be sore tomorrow from all the contorsion!

Edit: the colors of the wires at pins 9, 12 & 13 on the car’s connector match the wiring manual colors, that’s good to know too!
 
Discussion starter · #29 ·
I'm curious if the rear fog + line is always hot, and the rear fog - line goes to ground when the button is pressed.
Interesting!

If it was the case would that mean the fog light circuit would be “opened” until the line is routed to that switchable ground upon pressing the fog light switch?
@ControlNode any idea where that G401 ground would be? That is probably something else I can check before I try pins 9, 12 & 13.
 
I'm curious if the rear fog + line is always hot, and the rear fog - line goes to ground when the button is pressed.
Interesting!

If it was the case would that mean the fog light circuit would be “opened” until the line is routed to that switchable ground upon pressing the fog light switch?
@ControlNode any idea where that G401 ground would be? That is probably something else I can check before I try pins 9, 12 & 13.
No, the ground is not switched on this, G401 should be near the right tail light if I remember right. G401 may be not used without Rear center fog light or Reverse Parking Assist as those are the only things the manual shows using that ground. G405 should be almost next to Where G401 would be.
 
The book appears to have multiple markets info in it, I know it is for my car though as it has Sync3 info, NA was only market with that in 2016. But in the same logic it list non-Sync3 info, and we know all of NA RS came with Sync3 only.

This info is more of test at owe risk: The wiring for the rear fog does not show these pins as related, but looking at the C2280B connector view there are several pins in addition to 10(RD-BK) that show that same Circuit ID (CLS45) and list (FOG LIGHT REAR +) as the function. Pins 9(WH-GN), 12(VT-GN) and 13(VT-GN).
More Info on those pins from section 90 and shows the connector view info to be misleading:
C2280B
9 - Stop Right Rear
12 - Stop Left Rear
13 - Park Right Rear

The the diagrams in 90 can't even agree on how the rear lights are wired, on page 90-3 it has them as pins 19 and 20 of C2280B, but the connector view has those as open, but on page 93-1 it has reverse going through C2280E (pins 19 and 20), the connector view for C2280E shows these are for Rear Fog lights.

Basically Ford has released the most **** Electrical Diagram I've every really looked at.
 
Discussion starter · #33 ·
More Info on those pins from section 90 and shows the connector view info to be misleading:
C2280B
9 - Stop Right Rear
12 - Stop Left Rear
13 - Park Right Rear

The the diagrams in 90 can't even agree on how the rear lights are wired, on page 90-3 it has them as pins 19 and 20 of C2280B, but the connector view has those as open, but on page 93-1 it has reverse going through C2280E (pins 19 and 20), the connector view for C2280E shows these are for Rear Fog lights.

Basically Ford has released the most **** Electrical Diagram I've every really looked at.
Crap now there are even more possibilities based on which section you refer to! That does sound like a pretty bad wiring manual indeed, hopefully one or the other set of info is right!

And now I remember how I left connector C2280E and C2280F in that scrap focus thinking I would not need them, I threw them on the backseat guess maybe I should go back and grab them just in case the pins are different and have some spare plastic casings in case I crack one during dismantling!

Curious to check if there are pins at C2280E 19/20 now! Will check this too next time. Would be too good to be true if that turns out to be the right pins!

Thanks again for helping me you’re definitely dedicated to providing helpful info and making this work this is appreciated!
 
Crap now there are even more possibilities based on which section you refer to! That does sound like a pretty bad wiring manual indeed, hopefully one or the other set of info is right!

And now I remember how I left connector C2280E and C2280F in that scrap focus thinking I would not need them, I threw them on the backseat guess maybe I should go back and grab them just in case the pins are different and have some spare plastic casings in case I crack one during dismantling!

Curious to check if there are pins at C2280E 19/20 now! Will check this too next time. Would be too good to be true if that turns out to be the right pins!

Thanks again for helping me you’re definitely dedicated to providing helpful info and making this work this is appreciated!
I think pins 19 and 20 are the reverse lights, but in one area it shows them on C2280B, and in another in C2280E. Then in the Connector view it appears that they coded all lights to the rear of the car as Rear Fog Lamp just to make it confusing. Just bad info, should be labelled right.

Also, looking here it makes it sound very likely that a software change is also needed.
 
Discussion starter · #36 ·
@Barroux see PM. I referenced those old wiring diagrams before I bought the ebay book and they're not correct for our car.
Thanks for your PM, just replied a few minutes ago!

Thanks for your help I wont be working on the car itself for a few days life and work are keeping me busy these days, but I’ll sure plan the next trials as much as possible reading through what you guys provided in tha last few days!
 
Discussion starter · #37 ·
Oh and I received my diffuser yesterday but all but maybe one mounting tabs are broken which was not mentionned in the add and obviously when I asked about any damage they did not mention this either! Will be looking at my local plastic welding shop to fix those before installation. I got it for cheap so it’s still worth it if they can fix it, the whole tabs are there but broken at one or the other edge from being pried off the bumper cover I guess.

Otherwise it looks pretty good it only has one small scratch which will be barely noticeable once installed.
 
Discussion starter · #38 · (Edited)
I think pins 19 and 20 are the reverse lights, but in one area it shows them on C2280B, and in another in C2280E. Then in the Connector view it appears that they coded all lights to the rear of the car as Rear Fog Lamp just to make it confusing. Just bad info, should be labelled right.

Also, looking here it makes it sound very likely that a software change is also needed.
I started looking at the other forums with Forscan info they all refer to the same line but my asbuilt info from ford did not have this line. I’ll have to request a new trial license and connect to my car to see what I can find there. I think the link you posted is specific to front fogs though but there is info about Mustangs on the Forscan forums and info on Fusion forums about the rear fog. They all refer to the same line which hopefully would be the same for the Focus. It has been confirmed on the Fusion (with supporting wiring mods) but I dont remember seing any success story about the Mustangs...

I went back to the scrap yard and picked the two connectors C2280E and C2280F in case I need anything from those at some point.

Thanks
 
I started looking at the other forums with Forscan info they all refer to the same line but my asbuilt info from ford did not have this line. I’ll have to request a new trial license and connect to my car to see what I can find there. I think the link you posted is specific to front fogs though but there is info about Mustangs on the Forscan forums and info on Fusion forums about the rear fog. They all refer to the same line which hopefully would be the same for the Focus. It has been confirmed on the Fusion (with supporting wiring mods) but I dont remember seing any success story about the Mustangs...

I went back to the scrap yard and picked the two connectors C2280E and C2280F in case I need anything from those at some point.

Thanks
If you look at the options in this picture from that page one of the options is "foglight rear".
 
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