Classic/Antique Car Repair: 1980 Rolls Royce Ignition

Question
QUESTION: Good afternoon Vern,
Is their a way to check the distributor amplifier or ballest resistor on a 1980 RR Silver Shadow II?  In previous correspondence with me you had suggest that they may be my problem.  One additional thing that I have noticed is the coil seems to have a constant voltage on it and it doesn't discharge until the starter switch is turned off.  Thus firing once.  Any help?

Thanks,
Bill

ANSWER: Not That I am Aware of. What exactly is it doing?
I have had both the coil and the ballest resistor replaced.
A bad ballest resistor can produce several symptoms. The most
common is shutting of the engine while driving. However, a
bad coil could cause the car to run rough or hard to start or
not start at all. I guess even a bad coil could stop firing in
the middle of driving.

---------- FOLLOW-UP ----------

QUESTION: My 1980 RR Shadow II has no spark to the plugs. Took resistance readings on the existing coil. Side to side (primary winding?) was .7 ohms.  Side to middle = 4.95 K ohms.  Voltage to + coil terminal was 11.48 volts.  Voltage to negative coil terminal was .648 volts.  Thought coil was weak so replaced coil with NAPA ECH IC 277.  Still did not start.  Took resistance readings from center of distributer cap (coil wire side) to connection that rides on the distributer rotor.  No continuity so replaced the distributer cap.  Still did not start so replaced the distributer rotor.  Still does not start.  The voltage to the new coil positive terminal is 5.93 volts.  The voltage to the new coil negative terminal is 1.45 volts.  Don't know why the change in voltage. Any suggestions on what to do next would be greatly appreciated.  I had started the car and backed it out of the garage befor it died.  Started it again after some difficulty and drove it back in the garaage.  Have not been able to start it since--8-9 days.  
Thanks,
Bill




Answer
Hi Bill:
I notice you check the coil and replaced,
but what about the plugs themselves? If OK,
then the problem is mostly in the Amplifier
inside the distributor or the Ballast Resistor.

Inside the distributor there is a small circuit board
with a silver amplifier on it. This kit can be removed
and replaced.

The Ballast Resistor is a silver steel plated unit mounted
on the firewall that control current to the coil.

Either the Amplifier is bad...not enough current to the plugs, or
the Ballast Resistor is bad...no current to the plugs.

Answer
Hi Bill:
I think you have the wrong coil.
I believe coil NAPA Coil IC277SB 12V does NOT require an external resistor and
you car has a external Ballast Resistor. See my original post below...

Try using Coil ECH IC88 (but make sure it states: REQUIRES EXTERNAL RESISTOR)