1996 Ford Aerostar Owner's Manual - Page 203

When turning, drive slightly beyond the normal turning point so the trailer wheels will clear curbs or other obstructions. When stopped in traffic for long periods of time in hot weather, place the gearshift selector lever in P (PARK) to increase the engine idle speed. This aids in engine cooling and air conditioner efficiency. If the engine overheats, move the function selector knob to VENT to stop the compressor and increase the engine speed for a short time. RWARNING Do not tow a trailer when using a temporary spare tire. Vehicles with trailers should not be parked on a grade. However, if you must park on a grade, place wheel chocks under the trailer's wheels as follows: u Apply the brake pedal and hold. u Have another person place the wheel chocks under the trailer wheels. u With the chocks in place, release the brake u Apply the parking brake by pressing the pedal, making sure the chocks are holding. brake pedal down firmly with your right foot while applying the parking brake with your right hand. u Shift the gearshift lever into P (Park). 222