Retro Rockets is a distributor of PerTronix
Ignition Systems
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Ignitor
Troubleshooting
We occasionally get Ignitors sent back from customers as faulty.
In the great majority of cases the unit checks out fine indicating there
is something amiss with the vehicle. The
most common reason for an Ignitor not to work is low voltage.
If the red wire is connected to the coil + terminal the voltage there is
usually reduced by a ballast resistor or a resistor wire from the ignition
switch. Voltages over 8 will fire
an Ignitor in a 12 V system. However,
the voltage can be lower if the resistance in the circuit is higher than it
should be resulting in misfires or no spark at all.
This can be caused by loose electrical connections, corrosion at
electrical connections or deterioration of a resistor wire due to age or
neglect. In cases of low voltage
the red wire should be connected to a full 12 V source from the ignition switch
as mentioned in the instructions. The
power source must come through the ignition switch so that there is no power to
the Ignitor when the engine isn't running.
If there is power to the Ignitor when the engine isn't running and the
engine happens to be stopped in a position analogous to points closed, the
Ignitor will continue to try to charge the coil.
The current in the Ignitor/coil circuit will have no place to go except
into heat. This could damage the
electronics in a standard Ignitor. The
Ignitor II has an automatic shut off feature to prevent any damage under these
circumstances.
Another thing that can cause a problem with an Ignitor is if there is a bad ground
between the breaker plate on which the module mounts in the distributor and
battery negative (assuming a negative earth system).
With a digital ohmmeter set on its most sensitive scale, measure
the resistance between the Ignitor mount plate and the battery negative terminal
(the battery terminal itself, not the connector on the ground cable).
If it is 0.2 ohms or more you have a bad ground.
Check for corrosion at the connections of the ground strap between the
breaker plate and the distributor housing and also at the battery itself or
where the negative battery cable attaches to the block.
Another possible resistance source is the distributor hold-down clamp
which is the electrical connection between the distributor and block or intake
manifold. If engine parts have
recently been painted there may not be a good ground.
0.2 ohms may sound like a negligible amount of resistance, and in a
steady state circuit it often is. But in
an ignition circuit where the current is switched on and off many times a
second, the transient effects of the 0.2 ohms is significant and can prevent an
Ignitor from firing normally. |