MG Car Repair: 71 MG Midget, No Spark, high tension wire, coil wire

Question
QUESTION: Ok, So I will try to explain this as clearly as possible.  I have a 71 MG Midget with the original Lucas points still on it.  I have not been able to get a spark at the spark plugs, so I took the distributor cap off and did the test where you 1. Pull the high tension wire off the distributor but still have it hooked up to the coil, then put wire close to the engine block so you can see a spark.  2. Then turn the ignition on.  3.  Manually open the points in the distributor.  When I do this I clearly get a good strong spark from the ignition coil, but when I then attempt to turn the engine over by key there is NO spark.  It seems that as the engine spins and continually opens and closes the points the ignition coil wire should spark just as it did when I manually opened the points.  But it does not and I am officially stumped.  Also, I checked to see if the contact points open when being turned by engine power and they do.  So everything I can think of seems to be in order.

ANSWER: Hi Dennis,
Do this, turn the engine by hand until you see the points closed and turn the key on and test the (-) side of the coil for voltage. There should be none. Turn the engine by hand until the points are open and test the (-) side of the coil for voltage, you should have 12v+ (battery voltage)
This confirms that the points are electrically doing what they are suppose to do. If you don't get what you are suppose to see in voltage then some thing is wrong at the points. An insulator not in position or something of that sort.
Howard

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

QUESTION: Ok, so when I measure from the negative side of the coil whether the points
are open or closed I get 12volts...I have a solid white on the positive and a
white/black (goes to the distibutor) on the negative. I just don't understand
how the coil puts out 12volts to the negative side regardless if the white/black
wire is hooked up.  So I'm just making sure that this means something is
wrong in the distributor.

Answer
Dennis, when you see 12v on the negative side of the coil with the points closed it means the points are not grounding as they should. The points are a dead ground. It is impossible to have 12v on a grounded wire. So fix the points. Look at the little ground strap on the points plate or clean the contacts. That for sure is your problem.
Howard