I'd say take the batwing off the riser ( held on by 2 pins) and then disconnest the roof top wiring.
Use a ong piece of coax and connect it to the amplifier, bypassing the wiring inside the trailer.
Have someone hold it up, and go see if your tv works.
If it does, You got wiring trouble, if it does not, then you shoud check the amplifier by plugging in the coax from the antenna directly to the tv. reception will be very snowy, but if there is reception, then you kow the batwing is ok, and the problem is likely in the ampifier or the wiring inside the trailer. so, if the batwing is good, then put it back and try the wiring with the tv, but bypass the amplifier. Another thought : Is the TV ok?