Hey Tara:
Yep, these horns are pretty cheaply made, unlike the old 60'-70's horns that you could lay on for hours at a time for a wedding, etc. It seems to me that your horns should be under the Ford Factory Warranty for 3 years, 36,000 mile or longer, if you have an extended warranty? Make sure and check on that too w/ Ford.
I just bought a 2023 Ford Transit T350 (1 ton) cargo van and it came with a really cheesy "single" horn. I went onto the Transit USA forum and found a guy that had installed "Dual Note" (2 horns) on his Transit van. The Ford Dealer told him $175 for adding a dual horn. His single horn was a FIAMM USA made horn. He had a link to a YouTube video about changing these singles to dual note horns. The video said to buy the horns on Amazon FIAMM 7201622 for $28.00. I bought those horns on Amazon for $28 and even though the little metal mounting bracket didn't fit (because this Amazon model is a universal bkt.), the YouTube video said to just unscrew the Horns from the Amazon bracket, toss it and screw the horns onto the existing Transit bracket. Mine, with only one (1) original FIAMM horn, already had a second arm for the second horn so I bolted both horns onto the original Transit bracket and it was done in 30 minutes and, they work perfectly. And, so much louder and clearer now. I put my horns in from the top and I did have to remove the driver side headlight assembly but that took 5 minutes out & 5 minutes, back in, per the YouTube video. The video said to make sure the horn opening was facing as straight down as possible to keep water out. I've been in rain and deep road water with NO problems yet.
In your Expedition case, I would look on YouTube and see if there's a video for Expedition horn replacements. Since you already have 2 horns, you should be able to bolt these Amazon FIAMM horns right to your original Expedition bracket. The 2 electrical connectors are simply push-on spade connectors. Very easy 5 minute plug-ons. These FIAMM horns work great but I read some reviews that said if you blast them continuously, like in a wedding, they will melt down and stop working. I have had these FIAMM horns on my van for a year now, used them 10-15 times and they are still perfect and still sound great! I am hoping this helps you some, Lance