Tip of the Day…Test Drive. If the unit you are looking at is a Class A, B or C, you will want to go on a test drive. Before starting the engine, check the oil, transmission, brake and other fluids. You should have already checked the tires as part of the inspection process.
Note how easily or difficult it is to start the engine.
Do the wipers and washers work properly?
Do all lights work as required?
Does the horn work?
Is the radio functional?
Do all gauges work?
Are there any warnings lights lit?
Is the engine running smoothly?
Does the transmission shift properly?
Do the brakes work smoothly?
Is there any excessive play in the steering?
Are the windshield and windows in good shape?
When you return from the test drive get out and place your hand or use a laser thermometer to check for hot tires and rims.
Check for any leaks under the rig.
Source: Tips of the Day