A used pickup truck can pull a camper as long as its towing specifications are fit for the job and its mechanical condition has been carefully inspected. An RV with a poorly maintained truck should never be used to tow, so use special care when purchasing a used model.
In recent years, automakers have made considerable advances in pickup truck design, allowing consumer-grade 2015 heavy-duty truck models with towing capacities of up to 30,000 pounds. A camper with a late-model or older used truck can still be used to tow as long as that truck's rated towing-capacity and gross combined weight rating (GWVR) are sufficient figures for the job and the truck comes fitted with the proper towing equipment.
Since towing an RV places extreme stress on a pickup's drivetrain, brakes and chassis, it is important to make sure the truck is properly maintained with no mechanical issues that could quickly become serious safety hazards. When buying a used truck that will be used for towing, bring a certified mechanic to check for problem areas. Each automaker releases official towing guides for their pickup truck models with full information on towing capabilities.