Wow 1994. Probably not very many trailers from that year still around. Let alone a manual. OTOH the manuals I've seen are all pretty generic and not much help. Your best bet is to get the model and serial numbers from all of your appliances - water heater, refrigerator, heater, converter and get the manuals for them. They should all be available online and will give you specific information on operation, maintenance and troubleshooting.
Also post some pictures if you can. Would love to see what they looked like in the 90's.
2011 Chevy Silverado Crew Cab 4X4
2009 210 WBS