was the battery replace recently, when you say "a new battery"?
if so, many times the battery wires get crossed and set off a resettable breaker/fuse that's inline, between the battery and the front of the trailer.
it's usually located along the A-frame of the tongue.
simply by pressing the black button, will reset the breaker/fuse, IF you have the battery wires correct.
and Zoe the Wonder Dog(R.I.P.)
'07 Roo 23SS pushing an '07 Chevy Avalanche
Equalizer WDH and Prodigy BC