Is it the CO or propane alarm? Mine is two different units.. CO is a smoke detector thing the propane alarm looks like a box on the floor. My co detector will chirp when its battery is low. The propane alarm, wired into the 12v system, will go off when the battery gets low on the trailer.
As far as the lights, you'll need to read the manual for the CO detector (if that is what it is) since they can all be different. I'd buy a new detector and put that in the RV and see if the thing goes off again. It could be just a bad unit.
Pat, Jen & Heather... Oh yeah and our trained attack trailer cat, Cinnamon
2015 ChevyHD D-Max
2014 Greywolf 26DBH