[Healeys] Healey "Security" Circuit

[Bob Spidell]

re: "The power will go to ground via the path of least resistance, so my theory is 
that an ignition system (capacitor, spark plug, etc.) has lots of resistance, 
so if the switch in the trunk is "on" then the black/white wire is not 
grounded. and when "off" the coil will ground itself out and no power will be 
making it to the dist. Right?" 


Correct. In a points car, when the cutoff switch is in the 'Off' position the coil is grounded. When I installed a Pertronix unit, I moved the terminal so the circuit was open in the off position, breaking current flow to the coil. 

The white/black wire has its own terminal on the cutoff switch; it's connected internally to ground in the 'Off' position. It should be connected (in a points car) to the coil primary terminal opposite the power lead--the same terminal where the lead to the distributor is attached; i.e. in parallel--else it would be a dead short (as it is, only the coil resistance prevents it being a dead short). 

Bob 


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Bob Spidell - San Jose, CA 

----- Original Message -----


When the switch in the trunk is flipped, is it supposed to be interrupting the 
black white ground or is it supposed to be grounding it out? 

The power will go to ground via the path of least resistance, so my theory is 
that an ignition system (capacitor, spark plug, etc.) has lots of resistance, 
so if the switch in the trunk is "on" then the black/white wire is not 
grounded. and when "off" the coil will ground itself out and no power will be 
making it to the dist. Right? 

If that's the case, I can isolate this variable in my not working ignition by 
disconnecting it in the trunk and making sure it isn't grounded. 

The wiring diagram does not indicate which side of the switch the black and 
white wire is actually on in the trunk. 

If not as described above, is it a "flow" item similar to the ignition light 
(charge/discharge) indicator? And if so, How do I then Isolate it. 





Jonas Payne 
PBR 
Cell: (702) 358-5084 
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