2012 Upfitter Switches
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
I could use some help. I want to wire one of my Upfitter switches to the harness that runs the trailer lights. I want to be able to flash my trailer lights using one of the switches. Looking at some material found here it appears that everything runs through the body light module.
I don't want to screw up that module, has anyone done this and can lend some advice how to accomplish this task? Maybe a Ford tech could give me some help? I would really appreciate any help.
I don't want to screw up that module, has anyone done this and can lend some advice how to accomplish this task? Maybe a Ford tech could give me some help? I would really appreciate any help.
Or do you mean, during the day when the running lights are off, you want to be able to toggle them on/off?
Pick one, because making it work both during the day and during the night will get complicated.
I believe the easiest way will be to interupt the lead running to the bumper plug for running lights with a relay. Use the NO or NC contacts depending on which way you want it to operate, as I described above. Then just power the relay with an upfitter switch output.
The trailer lights are already isolated from the truck lights, so should be no problem with backfeeding.
Tuned
Joined: Dec 2004
Posts: 357
Likes: 1
From: Washington DC
Running Lights On
I think you mean, at night when the running lights are on, you want to be able to toggle them off/on with an upfitter.
Or do you mean, during the day when the running lights are off, you want to be able to toggle them on/off?
Pick one, because making it work both during the day and during the night will get complicated.
I believe the easiest way will be to interupt the lead running to the bumper plug for running lights with a relay. Use the NO or NC contacts depending on which way you want it to operate, as I described above. Then just power the relay with an upfitter switch output.
The trailer lights are already isolated from the truck lights, so should be no problem with backfeeding.
Or do you mean, during the day when the running lights are off, you want to be able to toggle them on/off?
Pick one, because making it work both during the day and during the night will get complicated.
I believe the easiest way will be to interupt the lead running to the bumper plug for running lights with a relay. Use the NO or NC contacts depending on which way you want it to operate, as I described above. Then just power the relay with an upfitter switch output.
The trailer lights are already isolated from the truck lights, so should be no problem with backfeeding.
I was hoping not to run a wire from the trailer plug back to the cab and the switches. I thought it could be done from the body module under the hood. I'm not sure what you mean by NO and NC, [terminals on the relay?], and doesn't each upfitter switch have a relay already? It is going to operate just the trailer lights so it won't be drawing that much amperage.
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
I do mean when my running lights are on, I run with my lights on every time I tow, day or night.
I was hoping not to run a wire from the trailer plug back to the cab and the switches. I thought it could be done from the body module under the hood. I'm not sure what you mean by NO and NC, [terminals on the relay?], and doesn't each upfitter switch have a relay already? It is going to operate just the trailer lights so it won't be drawing that much amperage.
I was hoping not to run a wire from the trailer plug back to the cab and the switches. I thought it could be done from the body module under the hood. I'm not sure what you mean by NO and NC, [terminals on the relay?], and doesn't each upfitter switch have a relay already? It is going to operate just the trailer lights so it won't be drawing that much amperage.
NC = normally closed
Most relays have one set of each, NO and NC.
I don't have your later model truck, so I don't know where the various fuse blocks are located. But I would guess you can do this under the hood. All you need to do is trace the wiring, or check your manual for where the trailer fuse/relay box is located. I don't think you need to do anything with a computer module. All you need is to find the source of the wire running to the rear bumper. Probably either under the hood or under the dash.
Tuned
Joined: Dec 2004
Posts: 357
Likes: 1
From: Washington DC
NO = normally open
NC = normally closed
Most relays have one set of each, NO and NC.
I don't have your later model truck, so I don't know where the various fuse blocks are located. But I would guess you can do this under the hood. All you need to do is trace the wiring, or check your manual for where the trailer fuse/relay box is located. I don't think you need to do anything with a computer module. All you need is to find the source of the wire running to the rear bumper. Probably either under the hood or under the dash.
NC = normally closed
Most relays have one set of each, NO and NC.
I don't have your later model truck, so I don't know where the various fuse blocks are located. But I would guess you can do this under the hood. All you need to do is trace the wiring, or check your manual for where the trailer fuse/relay box is located. I don't think you need to do anything with a computer module. All you need is to find the source of the wire running to the rear bumper. Probably either under the hood or under the dash.
If I understand what you've posted correctly, I could take a relay and install it so that with the upfitter switch in the off position the trailer lights operate normally and with the switch on the trailer lights are off allowing me to flash the lights.
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
Correct. Very simple project.
Junior User
Joined: Feb 2010
Posts: 61
Likes: 0
I can't thank you guys enough for all the info on this thread. I had a general idea where the wires from the upfitter switches might be but the underdash area is just a jungle. Knothole...your photo saved me a whole lot of time and aggravation. It made my day. I located the wires in about 30 seconds. Thanks again!!!
New User
Joined: Nov 2013
Posts: 24
Likes: 0
I am looking to add some Rigid D2 fog lights to my 2013 F250. I want to run them off one of my uplifter switches.
I guess the uplifter switches already have relays built in. These lights come with a relay harness as well. How should I go about wiring these up to the uplifter switch without screwing something up?
I appreciate the help.
I guess the uplifter switches already have relays built in. These lights come with a relay harness as well. How should I go about wiring these up to the uplifter switch without screwing something up?
I appreciate the help.
Mountain Pass
Joined: Jun 2012
Posts: 178
Likes: 1
These later model trucks have a "Body Control Module" that runs a number of things, one being the lighting. It's under the hood on the passenger side.
If I understand what you've posted correctly, I could take a relay and install it so that with the upfitter switch in the off position the trailer lights operate normally and with the switch on the trailer lights are off allowing me to flash the lights.
If I understand what you've posted correctly, I could take a relay and install it so that with the upfitter switch in the off position the trailer lights operate normally and with the switch on the trailer lights are off allowing me to flash the lights.
I intercepted circuit CBP30 (between the splice and the trailer tow relay), so now my upfitter powers up the trailer light relay. Note- I did not "T tap" into that wire. I cut and insulated the end going toward the BCM. I located that wire beneath the under-hood fuse block which requires removal of the driver's fender liner.
I also like it because it allows me to turn off the marker light function of my LED "line of fire" light bar, but also flash it when saying "thank you" without a trailer in tow.
If you would rather it be that when the upfitter is "on" it shuts the trailer lights off, you could always pass that circuit through a second relay to break the circuit.
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New User
Joined: Nov 2013
Posts: 1
Likes: 0
How can I check if my new F250 is prewired for factory upfitter switches.
Looking for guidance. I have a new 2012 F250 4WD with 6K miles and it does not have the upfitter switches in the dash. I have the factory trailer brake and beside the brake is a coin holder. The dealer parts department told me all I need to do is buy the switches and everything is there to connect in. I popped out the coin holder and I see no harness connector. How can I tell if my new truck has the harness already installed? I cannot find the relay assembly for the upfitter switches.
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
Looking for guidance. I have a new 2012 F250 4WD with 6K miles and it does not have the upfitter switches in the dash. I have the factory trailer brake and beside the brake is a coin holder. The dealer parts department told me all I need to do is buy the switches and everything is there to connect in. I popped out the coin holder and I see no harness connector. How can I tell if my new truck has the harness already installed? I cannot find the relay assembly for the upfitter switches.
New User
Joined: Jan 2014
Posts: 5
Likes: 0
connect kc fog lights to upfitter switch
Hi, I have a 2012 f250 that came w/ upfitter switches. I was wondering if I wanted to hook up kc fog lights to the upfitter switch is it necessary to still ground the lights or do I just connect the harness to the switch?
Hotshot
Joined: Aug 2006
Posts: 17,398
Likes: 317
From: Whittier, CA
Yes. For an electrical device to work, you must have a connection to voltate potential (the upfitter switch output wire) and a connection to ground (the trucks frame).
Be cautious of current draw of the lamps and the rating of the switch. You might need a relay. Frankly, if you have to ask that question, you might want to get someone knowledgable to help you. No offense intended.
Be cautious of current draw of the lamps and the rating of the switch. You might need a relay. Frankly, if you have to ask that question, you might want to get someone knowledgable to help you. No offense intended.
New User
Joined: Jan 2014
Posts: 5
Likes: 0
I understand the concept of electrical work Bill and grounding wires, however some people on other forums tell me the upfitter switches are already grounded and it not necessary. I find it hard not to take offense to your reply, just wanted to ask around and see if anyone else has anything different to say.
Elder User
Joined: Jul 2013
Posts: 521
Likes: 1
From: Dunnellon, Fl
I understand the concept of electrical work Bill and grounding wires, however some people on other forums tell me the upfitter switches are already grounded and it not necessary. I find it hard not to take offense to your reply, just wanted to ask around and see if anyone else has anything different to say.
It's all about our trucks !