1997 Ford F250 Owner's Manual - Page 250

To avoid damaging your vehicle or your battery, and to avoid injury to yourself, follow these directions for preparing your vehicle to jump-start and connecting the jumper cables in the order they are given. If in doubt, call for road service. Preparing Your Vehicle 1. Your vehicle has a 12-volt starting system, so you need to use a 12-volt jumper system. You will damage your starting motor, ignition system, and other electrical parts if you connect them to a 24-volt power supply (either two 12-volt batteries in series or a 24-volt generator set). Do not disconnect the battery of the disabled vehicle. You could damage the vehicle's electrical system. Park the booster vehicle close to the hood of the disabled vehicle. Make sure the vehicles do not touch each other. Set the parking brake on both vehicles and stay clear of the engine cooling fan and other moving parts. Check all battery terminals and remove any excessive corrosion before you attach the jumper cables. Turn on the heater fan in both vehicles. Turning on the fan helps protect the electrical system from voltage surges. Turn off all other switches and lights in both vehicles to prevent possible damage to either vehicle's electrical systems. 2. 3. 4. 5. 251