Ignition System: Service Precautions

Electronic ignition systems have entered an output range where body contact with live secondary terminals may be lethal. It is vital that technicians observe these safety precautions when working on a transistorized ignition:

1. Before checking compression or adjusting valves, switch off the ignition and remove the control cable from the ignition control unit.

2. People with pacemakers should not work on these ignition systems.

3. Do not touch or pull off any of the ignition system components while cranking, or with the engine running.


To avoid damage to the ignition system:

1. Disconnect cables from the ignition control unit only with the ignition switched off.

2. Do not connect any test lamp to coil terminal 1.

3. Do not short terminals 1 and 15 of the ignition coil to ground (e.g. as for a burglar alarm).

4. Do not crank the engine over without either disconnecting the control cable to the ignition control unit, or making sure that all parts of the ignition system are connected properly.

5. In order to avoid damage to the ignition control unit:
a. The high tension side must be loaded with at least 6K Ohms (distributor rotor = 1K, cap = 5K per connection).
b. Do not install a 5K Ohm distributor rotor for radio suppression.

6. To check for spark while cranking, do not hold the distributor end of the coil wire near a ground. Instead, pull the coil wire out of the coil to create an air gap and check for spark there.

7. For better heat dissipation, the control unit is mounted to the car with a conductive paste. Use a similar heat conductive material when replacing the unit.

8. During replacement, do not remove the protective foil from the control unit as it does not impair heat dissipation.

9. When doing any electric welding on the vehicle, disconnect the battery, alternator, switching unit, and any other IC controlled devices.