Old Person Bought Old TrailManor - Questions

[KERVBIZ]

Hello everyone! I just bought a 1995 TrailManor 3023. I've read a lot of information, and done some work on the trailer, but still have some questions, I actually have the original documents on the Trailmanor, the frig, brakes etc.

Here is my questions.

1. I don't see a carbon/propane detector anywhere - is this supposed to wired into the system? If not, any recommendations on a good battery brand?

I replaced the battery, everything works EXCEPT, i don't have any lights on the little unit by the frig showing battery power, water level - i have lights and power when i turn on the frig fan and the bathroom fan.

I don't see the motherboard or any breakers anywhere.

One of my seats has a piece of plywood on hinges, under this is a thin piece of wood were the heater is at and the water storage - why is this plywood piece hinged and under the seat?

Has anyone purchased a lowes or home depot cabinets for over the sink and stove, if so what model #? I can't see spending 650.00 on one cabinet, so i ordered the brackets.