I bet it is getting its power from the backup light. No need to run special wires upfront. This will make it tougher to bring a switch up front.

 

I'm sure my favorite cheerleader will come along and inform me of how faulty my logic is, but here goes anyway. If the backup alarm is an after the fact accessory, my guess would be that it is powered by the reverse light circuit. IF this is the case, pulling fuses isn't going to get you anywhere.

No matter how it is installed, I would first locate the alarm itself, isolate the power wire, install a relay and wire that to an upfitter switch. That way you don't have to fumble with turning it on and off when you back up but you can disable it for all other ocassions.

 

And since we are solving the mysteries of the universe... Does anyone know what these wires are for? Left side of the truck near the spare tire. They are capped.

 

You might have lucked out - it looks like that wiring is outside the harness that runs the length of the frame so it may be on its own circuit unless there is a nearby splice not seen.

 

Those capped plugs are for fifth wheel/camper wiring.

 

Hi Deere. I came to that same conclusion on the post before yours. It truly is aftermarket. As you can see from the pictures the wires are run in a different conduit.

I like your idea of using one of the upfitter switches. I could decouple it from the backup light and hopefully find the same coupler and make a cable up to the cab and connect it to the upfitter. From what I can tell, there is no relay in this circuit. It looks like a straight run from the lamp to the alarm. Will know more when the good doctor performs a backuplightology.

 

Thanks! I knew they had a purpose just not sure what...

 

My ears perked up when you said fifth wheel wiring...

Is one of those for the in-bed plug? I haven't put one in yet and my 5th wheel is just plugging simply into the under-bumper plug. I was planning on installing one of those T type extensions but if there is a better Ford solution, I'm for that.

To the OP: sorry for the hi-jack.

 

Well my thought wasn't so much to use an existing relay as it was to actually install one that would be activated by the upfitter switch. That way as long as the upfitter switch was on, the alarm would work when the reverse lights are activated just as it was always intended to do. With the upfitter switch in the OFF position there would be no alarm.

 

No problem on the hi-jacking. As you know, I was inquiring about the 5th wheel as well. Good to have this information available in case the General gives me approval to look at 5th wheelers.

 

Sorry I didn't see this while I was typing the last post. For less than $50 you can buy the plug in harness from your Ford parts counter. All you have to do is drill a hole where you want to install it, mount it and plug the wires in basically giving the same setup as would come from the factory.

 

I get ya! Haven't had my second cup of coffee yet...

 

Ok. Found out a little more about the horn itself. Looks like Navistar makes it and International uses it on their heavy machinery. It sure sounds louder than 102 dB!

3582511C1 530-NAV Compact self-grounding back-up alarm, epoxy sealed, 12-24 V DC, 102 dB(A), twin core with Packard connector

 

The back up alarm is mounted on the frame just above the spare tire on the passengers side of the truck.. All you need to do to disconnect the alarm is unplug the alarm.. There is an orange cap hanging there but was unable to cover the connection with the cap so I black taped both ends of the connections...

While you are under the truck by the spare tire I would advise you to check the air pressure in the spare--- mine was at 36--- psi Problem solved!!!

 

I think the orange connector is for covering the tailgate connector when you remove the tailgate. (Couldn't take the sound anymore either I see!).