I'm somewhat befuddled with the wiring for an Allison 700 ignition and my
TR4A. I put this in back in 1988 or so, before Allison was bought by Crane.
Not sure if the Crane XR700 is the exact same. I lost my original booklet.
Here is the problem: The ignition works fine in the car. But, I took a look
at the XR700 instructions that Randall put a link to. It has a bunch of
confusing notes on the XR700 requiring ballast resistance in the ignition
circuit. As far as I know, the early Triumphs like my 4A did not have a
ballast circuit. (Side note: The way the ballast circuit works is that when
cranking, full battery voltage is delivered to the coil. When the engine
starts, and the key released to the run position, the circuit switches so that
voltage drops across a resistance, the "ballast resistance" so that the
voltage to the coil is @8v.)
The instructions for the XR700 say that if you don't have a ballast circuit,
you need to add one. It further states that any Lucas coil with internal
ballast (perhaps the early TRs are this way, not sure) need to be replaced.
My TR4A runs fine...but I'm thinking that maybe failure is waiting to happen.
I surmise that without a ballast resistor in the circuit, the ignition module
and coil might both be overheating.
Question: Has anyone put an Allison ignition into their TR2-4a, and what did
you do about the ballast resistor. Did you add one?
Thanks,
Chris
|