Were is the serial number on a 1992 wilderness camper

Layout and links to the manual at Fleetwood.

https://www.google.com/search?q=owners+manual+for+a+fleetwood+backpack+camper+2009+721+FB

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How do you set up the propane frig in a 1979 Terry travel trailer?

notify a rv shop

First, I'm not a camper tech, but I have worked on fixed and portable sewer systems. Get ready as it's a stinker.
* Clogged at toilet means your system is backed up and has dried out at toilet and or sewer system and/or it has not been drained, flushed in a long time. Either way your going to need to find an approved sewage drainage site and drain/flush your system.
with a bit of searching on you tube I found this link that may help you. Though if it does not work then you will probably need proffessional help from a RV sewer repair service.
https://www.youtube.com/watch?v=_zSpW1VwhA4
Aloha, ukeboy57

This unit uses R-22. Here is a link to the service manual:

www.bryantrv.com/docs2/docs/rvp/rvp6789mech.pdf

make sure all fittings are ti
ght to check for leaks a simple solution of soapy water in a spray gun will locate a leak

I would no advise it as most campers have very little strength in the roof section. If you really have to get on the roof then use a plank that rests on both edges and walk on that

Contact the manufacturer and provide them the Model number. If it is still in print they can provide you a copy for a fee.

slide on a Jayco 5th wheel has no power

RV water lines can sometimes be difficult to locate. But typically, by removing a panel or an accessible flooring section, Youcan successfully gain access to most of the fresh water plumbing system. The clue to a removable panel is to look for screws instead of staples holding them in place