maybe it’s too cold for your pressure switch as they do have temperature ratings. Ours is rated for -40 to 200 degrees.
is the port on your pressure switch facing up or down when mounted. if it faces up then moisture can collect inside the switch and freeze overnight and it won’t work until the moisture thaws.
It will look different from an RS3L. It doesn’t have the same bells. An RS3K is a little smaller. (You might know this already)
Oh ok. Nope didn’t know that. This whole REAL Train Horn thing is new to me. 
Oh ok lol The only difference is the bell sizes and the note that each horn plays. An RS3L plays a lower note of B inverted 7th while a RS3K plays a higher note of D# minor. An RS3L has bell numbers: 25(biggest), 31(medium), and 44 (smallest). Your RS3K should have bells 31(biggest), 37 (medium), and 48 (smallest). Hope this helps!
Here’s an Install Pic.
I love these things. If you’re within 50ft of the Truck you feel them in your Body.
In this Vid they are Mounted under the Bed, facing BACK and OUT the Corner of the Truck where the Exhaust Exits. So they are Aimed totally facing Away from the Camera. I need to get the Debris Shields for them, then I’m gonna turn them forward. 
Here they are Mounted Under the Truck:
Here they are facing the Camera now. It doesn’t pick up the Sound anywhere near as Loud as it is.
u should turn around the 44 bell…
How come?
Thats the Short one right?
The Main thing I wanna do is get them facing forward. It’s just been REALLY Cold here, and now were getting a Snow Storm pretty much every day up to Xmas, so I won’t be able to do it until after then.
How much of an improvement will a 9 Gallon Tank give me over the 5 Gallon I got in there now? 9 Gallon is the biggest I can fit, from what I saw tonight. I might be able to fit the 12 Gallon but I don’t think so.
9 gallon will give it more boost but u want that 12 gallon and maybe upgrade to a graham white valve.
It’s actually the 48 bell 
o it looked like the 44 or 41 but wasent sure