Question: Did they work when you first took delivery of the trailer? You may have a problem with grounding of the wires caused by staples, nails (caused during construction), or wire run may be chafing against a moving part (slide?). You may want to have an audio specialist check the wire runs for this. Point to remember, these Jensen units (I have one), were picked from the deep end of the audio equipment gene pool....
Roselyn and Darrell
2007.5 Silverado LT/EFI Live Tuned Duramax/6Spd Allison/Banks Ram Air with Super Scoop/Edge CTS Gauges/Air Lift Load Lifter 5000 Ultimate Air Springs
2014 335ss Cruiser Provincial