I purchased a used 2016 F250 about 5 years ago. It did NOT come with upfitter switches, however I did install those myself after the fact. When I flip the switches, the amber lights turn on so everything appears to be connected properly. I am now trying to install a light bar, but thought I would test it before going through all the wiring. If I connect the red (+) wire from the light bar directly to the yellow (aux 1 switch) wire inside the cab, and then ground the black wire from the light bar and turn the truck on and flip the switch, should that not power the light bar? I am asking because when I tried this I didn't get any reaction from the light itself. I am trying to test things before undertaking the entire project to determine if it is worth my time. Can anyone shed light on if my temporary connection just to test things should work? If not, what can I do to test it to make sure I have the wirings correct?

 

You wired the upfitter switches, no? Seems to me you might want to check how those are wired and if you have 12v on the common side of the switch. Just because the switch lights doesn’t guarantee you have 12v on the line/ common side of the switch.

 

When installing the upfitter switches, there were only two plugs, one to the back of the switches, and one to another grey plug up above the gas pedal. Not a great electrician, but that install seemed fairly straight forward. When I flip the switch, I can hear a click from what I have gathered is the relay turning on. As far as checking for 12v on the “common side”, how exactly would I do that?

 

There are a couple fuses in the fuse panels you have to add in. I think 2 are in the under hood panel and 2 in the interior fuse panel.

 

Fuses for switch 1 and 2 are located under the hood and fuses for 3/4 are on passenger panel. I didn’t check 3/4 as I’m not using those now, but there are fuses already in place for 1/2 both spots 83 and 94. Perhaps one of them is bad. I dunno. Will have to try that next I guess

 

Did you install the upfitter switch relay block as well and it has relays installed in it? I would assume you did. But worth mentioning.

 

Yes. There was about a 4 inch box with wires attached to two separate grey clips. One to the switches and one to another location above the gas pedal. I didn’t mount the box properly with screws, but I am guessing that doesn’t matter. It’s in the proper location just not “fastened” in place.

 

The upfitter wiring has the two grey plugs and a ground ring lug in the wiring, did you put the ground on also?

 

I’m guessing the ground is where the screw mounts it. I just got that done and tried the light bar in the cab again. The wires were connected and it briefly came on and flickered, probably a bad wiring on my part, then I couldn’t get it to work again.

Side note, anyone know what AWG I should use when doing the final wiring?

 

Depends on the fuse size protecting the circuit.

 

I think upfitter switch one has a 25amp fuse

 

12AWG wire minimum unless you change the fuse to smaller or put in an inline fuse. 10AWG might be best depending on the length of the circuit.

 

Thank you. Any idea what AWG the wires on the Upfitter switches, as well as the usable pass through wires? Would it be find to utilize those if they aren’t 10AWG?

 

Sorry I don’t. Mine was factory wired for strobes with the snow plow kit. I only used the last switch for the high idle mod.

 

Thank you all for the help. Got everything wired, mounted, and it is 100% operational. Appreciate the community’s willingness to help.