[Mgs] points

[Barney Gaylord]

Youi need a test light.  Very cheap tool.  See here:
http://mgaguru.com/mgtech/tools/ts129.htm

The contact points are switching the coil wire to ground.  With 
ignition on, when points are open there will be power on the wire 
from coil to distributor.  When points are closed the wire is 
grounded and will have no power, 0-volts, no light.

Alternately, you can disconnect the wire from coil to distributor, 
connect the test light to a live power source (lower fuse for 
instance), and touich the ptobe to the distributor terminal.  When 
points are closed it complets the circuit to ground, and youie get light.

You can also test points with an ohm meter connected between the 
distributor input terminal and ground on the engine block.  With 
points open it will read 50-megaohms (open circuit).  With points 
closed it should read 0-ohms (short to ground).  Resistance with 
points closed should never be higher tham 1/4-ohm 
(250-milliohms).  If resistance is too high you need to clean the 
contact points or fix a faulty connection.  It couid be corroded 
points, or a dirty wire connector, or bad contact between distributor 
body and engine block.


At 11:00 AM 5/9/2013 -0500, Monte Jane Morris wrote:
>I have an inductive timing light and a dwell meter. I need to 
>determine when my points are open or closed. Can I use one of the 
>above to do this and if so, how?
>
>Where exactly do I hook the alligator clips to use each one?
>....