First off welcome to to the forum. If you go up to the "USER CP" in the black bar at the top of the page and edit your signature you can can add the make, model and year of your trailer and tow vehicle. That will show up on every post you make and enable responders to better help you.
Yes you need the battery. The water pump runs on 12v dc and when you removed the battery the converter supplied it with 12v dc. You either have a bad switch or the previous owner wired it direct. Go to the power center and you will find a fuse for the water pump. Pull the fuse and the pump will stop.
The detector referenced earlier is a CO and LP leak detector that is wired into the 12v dc system. The smoke detector is typically AA or 9v dc battery powered like in your house.
There are 2 electrical systems in a camper. 12v dc (battery that's charged by the converter) and 120v ac that's supplied by shore power cord. The 12v dc powers the lights, Refrigerator control, water heater control, furnace control and fan, air conditioner control including thermostat) radio, tv antenna booster, CO/LP leak detector, Slide motors, Awning (if not manual), stabilizing jacks and tongue jack (if not manual), bathroom fan & any ceiling fan in a ceiling vent, range hood fan, and outdoor lights.
The 120v ac runs the 120v ac to 12v dc converter, the heating elements only in the refrigerator and water heater, the air conditioner compressor and fan, and all "standard" outlets like you have in your house. The television will be plugged into a standard 120v outlet that's typically behind it.
Hope this helps.
__________________
Marshall
2012 Laredo 303 TG
2010 F250 LT Super Cab, long bed, 4X4, 6.4 Turbo Diesel
|