Carb LS3 (LS376 / 515) Will Not Shut Off

[jigoe007]

LS3 engine installed in a '68 Camaro with an American Autowire classic update wire harness. I'm using an internal regulator Corvette alternator and I installed a Holley diode pigtail that is connected to a 12 volt switch wire that powers the tach gauge. In order to shut off the engine I have to turn off the fuel pump. Any ideas?

[andrewb70]

How is the ignition box powered?
The Holley alternator pigtail has a resistor, not a diode.
Andrew

[vette427-sbc]

If it is a diode, make sure the stripe is facing the alternator... Although if it was backwards the alternator should not turn on.

[jigoe007]

How is the ignition box powered?
The Holley alternator pigtail has a resistor, not a diode.
Andrew
The pink wire from the LSx controller is connected to the pink ignition switch wire. While the engine was running and with the ignition switch in the off position I had 0.6v at the pink ignition wire at the ignition switch so there shouldn't be power at the pink LSx controller wire when I turn the key off. While the engine was running I disconnected the three wire (pink- 12v power, yellow- tach signal, gray- ground) connector from the LSx controller and the engine stopped immediately while the key was in the run position.