This is a question that is really more about the curiosity of this issue. I both wonder what it is but also if others have seen it. When the ambient temp and humidity are just right there is a 50/50 chance that my car will not turn over. I can just about call it, when it's going to happen. Unfortunatly it is the worst type of electrical problem in that it is not consistent. It has done it for a few years now. I first wrongly suspected the relay and replaced it. Then I decided it must be the neutral safety switch and replaced that. No change and I can't get it to fail when I have the time to chase down the short. I always jump out and start it on the relay. Once this is done it is good for the day. I can start it on the relay and immediately shut it off and start it with the key. I suspect it is the switch or the firewall plug. The accessory power seems to function just no starter engagement. The car is a mess under the dash. Tweekers destroyed it. I will probably swap in the entire dash and steering column from a 73 Newport since I have one and intend on going to a keyed column anyway. Has anybody else experienced this type of failure?