Help with Electronic Ignition Conversion

79Rude115

Petty Officer 2nd Class
Joined
Aug 23, 2006
Messages
122
1990 OMC Cobra 5.7

In the process of converting over to electronic ignition with hot spark module and pertronix flame thrower 1.5 ohm coil. I got everything installed and using my stock coil and got the timing set to 8 degrees BTDC. It was running great but I took two additional steps that introduced a big problem.

1) Installed the flame thrower coil
2) Ran a wire from + on the coil to the ignition switch

After making these changes when I turned the key the engine cranked for a second then everything went dead. The volt meter showed only a couple volts with the key on and the engine would not crank at all. I unhooked the wire I ran from the ignition switch to the coil...still the same thing. I then pulled the purple wire from the ignition switch and the engine would turn over again. I then reconnected my wire to the coil and it started right up. I checked the purple wire under the dash and did not find anything abnormal. I then reconnected it to the ignition switch and everything seems to be working fine again.
I want to find out the root cause of this and avoid ruining all of the hard work on the electronic conversion. Any advice would be greatly appreciated. Is there a better place to tap an ignition switched 12 volt lead to the + on the coil? Was running the wire to the ignition switch a bad idea?
 

79Rude115

Petty Officer 2nd Class
Joined
Aug 23, 2006
Messages
122
Re: Help with Electronic Ignition Conversion

After looking over the wires under the dash I think the problem may have come from the kill switch as that is where the purple wire goes. I looked at the repair manual and the wiring diagram does not show a kill switch so I am having trouble understanding how it all works. Can someone give me a brief explanation of how the kill switch works so that I can try to test to see if the kill switch is the problem?
 
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