What lies behind panel in storage compartment backing up to where the stairs inside lead to bedroom?

Generally, on fifth wheels, the fresh water tank is in the rear area of the rv, but the pump is usually up near the front near the rest of the plumbing. Ie water heater, bathroom, etc. There are storage areas in the front, usually, the pump is on the side where the door for entering the trailer is. Open the storage access door that is on that side in the front and look at the panels that close off tbe storage area to the living quarters of the rv. There is usually a hole for access to a “winterizing point” marked. There us where you will find the pump

no idea, but I would look very close to the water tank, maybe as part of the fill cap.

If your model has the bed within the slide, in will be underneath the storage compartment under the bed frame. If there are cabinets, you will need to pull out a bottom drawer. Your camper should have a manual crack handle specific to operate that motor. Considering the age, you may have better luck with various have tools. Make sure you check the drive path for any obstructions to prevent damaging the rails.

Look in the storage compartment area behind a partition or wall. Most I have seen are behind those covers and are near the connections for water or the hot water hear back side behind that wall or partition. For the Montana's, if you go in through the door on the driver's side, it will be on the right.

While not familiar with that particular model, it will be easy to locate. Just turn it on and listen. It WILL make some noise.

Some are accessed from an outside panel, under a bed or cabinet, thru an access panel inside, outside or a storage compartment outside.

sounds like your converter running which is normal.

Wiring diagrams are not available as the manufactures to not publish them. There will be a series of circuit breakers that control the slide, jacks and awning. The circuit breakers are small rectangle 12v breakers with a terminal stud on each end. Some are automatic reset and others have a small black button on the side that must be reset. On a motor coach you will find these in a storage compartment and they probably will not be labeled. On travel trailers they will be located near the front of the trailer and often times will be linked together with a copper bus bar. On 5th wheels they will be located in the front storage compartment close to the battery box. Follow the positive lead from the battery back and you should locate them relatively easy. Next, make sure the nuts on the terminals are tight and using a test light make sure that you have power to each terminal on each circuit breaker. If you do not have power to the output side of the breaker then it is bad and will need to be replaced. They are amp rated so make sure you replace the breaker with the proper amp rating. I.e, 30amp or 40amp. In some rare cases the inline circuit breaker for the jacks is relatively close to the jack behind where the switch is mounted.

They usually locate them close to the kitchen or bathroom sinks. Often times they will be hidden behind a concealment panel in the storage space under the bathroom. You will have to possibly remove your items in storage behind the kingpin. On the drivers side of the unit inside the storage space there should be a carpeted panel that will have four screws holding it in place. Remove that panel and behind the "docking station" where all of the fresh water supply connects you should find the fresh water pump.

most likely in the front cargo area with acess doors on both sides,just front of the entry door .there are panels that can be removed. driver side has water heater and lines pass side would be like under the stairs to bedroom.most wiring converter and transfer switch would be there ,if unit has a generator