Welcome Anne,
Not sure what model 83 Sunline you have, but as a standard rule, Sunline installed brake axles on every camper model they made, all the way down to the tiny Sunspot campers.
If no one fiddled with the power cord that plugs into the back of the truck, there should be a 7 wire, large round plug that is needed for trailers with electric brakes. It they cut it off, and there is a 4 wire flat plug, then someone unhooked the brake system and that needs to be corrected.
The campers with brakes, and again most every Sunline had brakes, are required by most all state laws (maybe even federal) to have an emergency break away system to apply the trailer brakes in the event the trailer becomes unhooked from the tow vehicle when going down the road. This break away system needs to be working. And having brakes on the camper, helps your tow vehicle stop the whole system.
As to parts, this all depends on the brand of brake axle you have. Some of the older Sunlines had Hayes braking systems that have been discontinued while others had Dexter. Depending on the brand, parts may or may not be available and a braking system up grade would be needed.
As Jim said above, any time a used camper is bought, you should have someone who knows auto or trailer mechanics pull each brake drum, check each brake is working, clean them up to working order, and repack the wheel bearings with fresh good quality bearing grease. Having a wheel bearing go out on a camping trip, makes for a bad day camping. The axles, brakes, suspension are often an overlooked maintenance item that needs routine inspection.
If you need help with any of this, let us know. We are glad to help. Just ask.
John
