>Frank Sperling wrote:
>
>>I have a '79B and have always been suspicious of the current
>>coil...I'd like to replace it. However, I don't know if my car
>>has a ballasted or non-balasted ignition system. My questions
>>are:
>>
>>1) How can I tell which kind of system I have?
>>
>>2) What is a balasted system anyway?
>David Deutsch replied:
>>This is like the mystery question. At least to me.
>
Dave ... you don't know the answer? ... say it ain't so! ;^)
>
>>All I can tell you is that if you purchase a Lucas 40,000 volt Sport
>>Coil according to Victoria British Catalog ($38.45) " For cars with
>>ballasted ignition systems. The ballasted resistor or resistive
>>cable should be removed and the coil wired as explained in the
>>fitting instructions."
>
>>Well I just found in an old Classic British Sports Car (out of
>>business) MGB parts catalog that blasted systems were in all 75 -
>>models (unleaded). Think it had something to do with the electronic
>>ignitions they started using then. Helpfully someone with more
>>expertises will jump in right about now.
>
Well I certainly don't have more experience than Dave, but I can
confirm that, according to the Moss Catalog, that ballasted ignition
systems were fitted to the 'B' from '75 thru '80 in conjunction with
the new fangle electronic ignition.
I don't have a wiring diagram for a late model 'B', but I would
ass*u*me that the ballast resistor, Moss Part No 131-560, is fitted in
the primary circuit between the ignition switch and the low tension
terminal on top of the coil ... and an additional wire is run from the
starter solenoid to the same low terminal on top of the coil.
With a ballasted ignition cirucit, when the starter solenoid is engaged
the ballast resistor is shorted out, thus boosting the primary voltage
to the coil to assist in easier starting. IOW, the ignition circuit not
only
feeds the coil, but all sorts of other electrical bits ... when the
starter
solenoid is engaged primary voltage is supplied to the coil via the
wire from the solenoid.
Safety Fast! ... larry.g.unger@lmco.com
'61 MGA 1600 MkII
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