# ‘65 GTO Ignition Switch Problem



## Roqetman (Aug 31, 2015)

Hello Everyone, Happy New Year! The ignition switch on my GTO allows the engine to continue running when switched to Accessory. Here’s the deal, start the engine, switch to Off, then immediately to Accessory (key all the way to the left) and the engine keeps running. Engine does stop when I switch it to Off. I’ve replaced the ignition switch which is in-dash to left of steering wheel and I’ve replaced the key tumbler as well. It may not hurt anything but something is wrong and I’d like some advice on how to fix it. Picture for effect. Thanks, Roqetman!


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## PontiacJim (Dec 29, 2012)

Roqetman said:


> Hello Everyone, Happy New Year! The ignition switch on my GTO allows the engine to continue running when switched to Accessory. Here’s the deal, start the engine, switch to Off, then immediately to Accessory (key all the way to the left) and the engine keeps running. Engine does stop when I switch it to Off. I’ve replaced the ignition switch which is in-dash to left of steering wheel and I’ve replaced the key tumbler as well. It may not hurt anything but something is wrong and I’d like some advice on how to fix it. Picture for effect. Thanks, Roqetman!


I assume this was happening before and is why you changed the switch in the first place?

If it was ok before and you had no issues, then I would say you have a bad switch - even though new. If you were having this problem before and it is why you changed the switch, then you have a wiring issue.

Either way, you will need your wiring diagram to trace your wiring and do some testing to track it down - step at a time. :thumbsup:


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## Roqetman (Aug 31, 2015)

Thanks PontiacJim. I’ve tried to trace down the wires from the diagram but it was converted to GM-HEI and one wire alternator before I got it 2 1/2 years ago. The ign switch that was in the car when I bought it was doing the same thing and it was inconsistent about making contact, so I replaced it. I wonder how much having HEI ign and internal voltage regulator alternator would effect the ign switch wiring? The old voltage regulator on the firewall has also been removed. Do you know if any of this would change the wiring plug to the switch? It only fits one way. 
Thanks!


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## PontiacJim (Dec 29, 2012)

Roqetman said:


> Thanks PontiacJim. I’ve tried to trace down the wires from the diagram but it was converted to GM-HEI and one wire alternator before I got it 2 1/2 years ago. The ign switch that was in the car when I bought it was doing the same thing and it was inconsistent about making contact, so I replaced it. I wonder how much having HEI ign and internal voltage regulator alternator would effect the ign switch wiring? The old voltage regulator on the firewall has also been removed. Do you know if any of this would change the wiring plug to the switch? It only fits one way.
> Thanks!


I would not think anything would be different doing the swap. The key placed in the ACC position will provide power to other components of the car, ie radio, fan, etc., but should not supply power to the engine. Somewhere in the wiring one of them must have gotten incorrectly connected or a wire was added where it should not have been added.

I would start in the engine bay and work back to the ignition switch in trying to trace the problem. Try putting a test light on the wires at the Alt & Coil, testing one at a time, and then turn your key to the ACC position to see which one lights up. If one of them lights up, then you know which one is getting the power and then work back from there to trace it.

The other thing that comes to mind is that there can be what is called "electrical feedback." This can happen under certain conditions or by doing upgrades to the electrical components. The solution is the installation of a Diode. Read this and try this test: https://www.americanautowire.com/vi...t-continues-to-run-and-will-not-shut-off-why/ Here is another blog that details a similar problem and the Diode installation on the Alt. :Car wont turn off with ignition - Hot Rod Forum : Hotrodders Bulletin Board


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## Roqetman (Aug 31, 2015)

Thanks for the advice and links, that very helpful!


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## 64GTOConvertible (Aug 28, 2016)

"Converted to HEI" I think I see the problem...


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