I bought the TireMinder and had the same results. The booster seems to have solved the problem. I note that they now include it in the package (used to be optional). I got the booster just as we bought the 5th and it's installed in the basement on the door side. I got the 12V from a nearby light fixture.
We've got different TTs but I'd suggest near the front of the trailer and in an enclosed area (like a storage compartment). I think they are "weather proof" but I wanted mine inside.
I really like having the sensors to keep an eye on my pressures. It may be like taking your umbrella, if you do it won't rain.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks