Ray,
The Crane unit in my autocross car, with the Lucas Sport coil, has been
in for about a year. The daily driver has had its Crane unit for about a
year and a half. The latter has an aftermarket 12v. coil. So far,
neither of my units has gotten hot or burned out.
In the first paragraph of my instruction sheet for the XR700 states "The
XR700 requires ballast resistance to limit coil current." My
instructions make no referral to limiting voltage or current to the
XR700 itself. Nowhere in my instructions is there any mention of
limiting voltage going to the XR700.
Charlie B.
>
> >I'm running a Crane XR700 and an after market 12v. coil, with the
> >ballast resistor wire bypassed, on both my Spits. So far I've had no
> >problems with my Crane units. The Crane unit doesn't care if the ballast
> >is external or internal to the coil. Other units . . . I'm not so sure.
> >The Crane instructions do indicate that if you're using a non-ballasted
> >coil, external resistance must be used.
>
> The real issue here is not the voltage applied to the coil,
> but the input voltage applied to the Crane unit. My crane unit (on
> 1500 cc Midget; same engine) requires 6V, not 12 V, which is
> not very clear from the instructions which serve to confuse the issue
> with the language Charlie quotes above.
>
> If the Crane unit is powered by the 12 V input, it will run fine--
> for about 5 months, at least in my experience. My unit is now
> driven at 6 V, by the use of the ballast resistor, and it has been
> trouble-free for probably two years.
>
> I suggest to anyone who has installed a Crane unit, and had questions
> about the ballast resistance language, that you should reread the
> ambiguous directions with my interpretations in mind, and if you
> are running a crane unit at 12 V, rewire it for 6 V. If the Crane
> unit is too hot to put your hand on it while operating, there is
> something wrong, and you can expect a premature failure.
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