Download Old Distributor Removal: Note: Ensure the vehicle ignition switch is in the off position and battery is disconnected before attempting the installation of the Vertex ® Electronic Distributor. Step 1 -Disconnect the coil trigger wire coming from the distributor to the negative (-) side of the ignition coil at the coil terminal. Disconnect the wire supplying current to the positive side (+) of the ignition coil. (Note: there may be two wires connected to this terminal, one from the ballast resistor and one from a terminal on the starter solenoid.) Identify this wire(s) for future reference as the coil+ wire(s). Remove the old ignition coil as this is no longer needed. Use a shop service manual and locate the spark plug wire that is used to set the timing (usually spark plug wire #1) and mark this wire location on both the distributor cap and the distributor housing. Step 2- Rotate the engine crank shaft in the direction of proper rotation until the timing mark on the harmonic balancer lines up with the indication on the timing tab for TOP DEAD CENTER (TDC). See a service manual for these locations. Step 3- Remove the distributor cap (do not remove the spark plug wires and coil wire from the old distributor cap at this time) and observe the position of the rotor blade. The blade of the rotor should line up with the mark placed on the old distributor housing (step 1). If the blade is not lined up with the mark (180 degrees away) then repeat step 2 until the timing marks are aligned again.