Just to round off this thread I've had a detailed answer to my questions to Lumenition ( Autocar sales ).
Here they are posted with their permission of course.
> Tony,
> 1. Short bursts of high current on starting will not harm the coil or the power module. In addition battery voltage under load will probably drop to around 10.5 V, so the maximum current through the 1.5 Ohm coil is more likely to be around 7 Amps.
> 2. A connection can be made from the coil positive to the starter motor relay connection without harming the module or the coil as noted above.
> 3. The MS3 coil and ballast resistor combination has been replaced by the MS4. For both coils a connection can be made from the coil positive to the starter motor relay without causing any problems.
> If you vehicle had a cold start function before the Lumenition ignition was fitted there would have been a ballast resistor in circuit already. this might have been a separate resistor similar to the BR1 ballast resistor supplied with the MS4 (and MS3) coil but it might also have been a resistive wire fitted in the wiring loom. if you do have a ballast resistor already fitted on the vehicle you can use that instead of the one supplied with the MS4 coil.
> What you should not do is use both, as this will cause progressively weaker sparks as engine speed increases. So it is worth checking if an original resistor is fitted and if so that only one of the resistors is in circuit
Explanations and information is available on our websites at Lumenition.co.uk, Autocar-electrical.com and Autocar-electrical.co.uk.
The main link is
http://autocar-electrical.co.uk/product-info
> Yours sincerely
>
> Autocar Sales Support
> Steve
> Please visit our website at
www.autocar-electrical.co.uk for information and dealer listing for all our product ranges.
HTH,
Tony.