1997 Ford Aerostar Owner's Manual - Page 238

Use specially formulated windshield washer fluid rather than plain water, because specially formulated washer fluids contain additives that dissolve road grime. For safety reasons, washer fluids containing an appropriate antifreeze such as methanol should be used in freezing weather (temperatures below 32˚F [0˚C]). State or local regulations on Volatile Organic Compounds (VOCs) may restrict use of the most common antifreeze, methanol. Washer fluids containing non-methanol antifreeze agents should be used only if they provide cold weather protection without damaging the vehicle's paint finish, wiper blades, and windshield washer system. If you choose to use a windshield washing solution that must be mixed, follow the manufacturer's mixing instructions. Improperly mixed solutions may freeze unexpectedly. RWARNING Windshield washer fluid contains methanol which is poisonous. Checking/adding the washer fluid for the liftgate Check the liftgate washer reservoir regularly. This is not the same reservoir your front windshield wipers use. The opening for this reservoir is on the right side of the liftgate above the tail lamp. A fill cup is located on top of the right hand tail lamp and is accessible when the liftgate is open. Close the fill cup cover after filling and before closing the liftgate. Refill this reservoir with the same solution you use for your windshield. To find out how much washer fluid the liftgate reservoir holds, see Refill capacities in the Index. 239