- a) Before connecting the auxiliary battery, make sure that the ignition key is turned to the "OFF" position.
- b) Turn off all lights, heater and other electrical loads.
- c) Take care to protect your eyes. It is best to use protective glasses.
- d) Make sure the booster battery is rated for the same voltage as your vehicle's battery.
- e) Two vehicles must not touch each other under any circumstances!
- f) Make sure the transmission is in neutral (manual transmission) or "P" (automatic transmission).
- g) If the booster battery is not a maintenance-free type, remove the vent caps and cover the vents with rags.
Connect the heavy gauge red jump starter cable to the positive (+) terminals of both batteries. Connect one end of the black jump starter cable to the negative (–) terminal of the booster battery and the other end to a properly grounded point on the vehicle you are trying to jump start (for example, a bolt or bracket on an engine block). Make sure the wires do not touch the fan blades, drive belts or other moving parts of the engine.
Start the car, then, leaving the engine running at idle speed, turn on the heater voltmeter motor (at maximum speed) or a rear window defroster to smooth out any voltage surges that may occur when the wires are disconnected (do not turn on lighting fixtures, as sudden voltage peaks may cause the lamps to burn out). Disconnect the wires in the reverse order of their connection.