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Discussion Starter #1
It seems that gremlins have invaded my electrical system. Various intermittent symptoms have shown up over the last few weeks. Now the car won't start at all. Here are the symptoms (all intermittent):

Makes a buzzing sound when I turn the key, sometimes only a single click.
The wire to the coil (HEI distributor) is always hot regardless of key position, which rapidly drains the battery.
When running, sometimes the battery charges, sometimes not.
Sometimes everything works perfectly!

I've changed the alternator, starter relay, voltage regulator, ignition switch, and the battery was tested and came back good. I thoroughly cleaned all contacts with a wire brush. What else could it be? My only other idea is that something isn't grounded properly somewhere. I chased the wires around according to the wiring diagrams, and everything seems to be in place. I'm baffled...

Here are a few pics to help out. It's a 1966 C-code. Thanks!
 

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I Have had more vehicles come in with those cheap red painted battery cable ends that wont start or are slow starting. I would start by replacing that batt cable with a complete factory made cable or at least put another Quality battery cable end on the cable. Usually they are coated completely with the red and it causes high resistance in the cable. Start there in my opinion!!! As for the HEI having power all the time you need to look at where it is being feed power from. Maybe someone has it connected to the wrong circuit. Should be switched battery voltage.
 

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If you have your coil wired up using the stock harness, it should be getting a full 12v only when in the crank position. When in the run position, the coil is fed by the pink resistor wire.

I just recently learned that it is possible for the starter solenoid to fail in a way that would explain your problem. The stock solenoid, when activated, closes the circuit to send juice to the starter AND the coil (this is where the full 12v comes from). It is possible for the solenoid to fail in that it always supplies that 12v to the coil but still switches the starter. Since your car has the constant 12v, and it sometimes cranks, I'd look at your solenoid as at least a contributing factor.
 

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Discussion Starter #4
I found out that it was indeed the solenoid. With everything hooked up and the key out of the ignition, I just happened to give the solenoid a little tap.....and the engine fired up! I ran around to turn off the key (it was in my pocket), ran back around and pulled the wire from the coil which shut down the engine. The starter was still cranking, however, so I tapped the solenoid again and it stopped cranking. I figured out that whenever I was out driving and hit a big bump, something shook loose in the solenoid to make it stop working correctly, and other times a bump would put things back in order - hence the intermittent nature of the fault.

I returned the solenoid to Autozone and upgraded to the Gold model. One more question: is it possible to put it in backwards? The schematic shows it upside-down, with the terminals at the bottom, which is the reverse of how the original was installed in my car. The terminals are not marked for positive,negative.
 

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Looking at your photo the solenoid is in upside down, should have been installed like the original. The two terminal in the middle should be marked "s" (start) and "I" (ignition). The "s" is the one toward the front of the car and the "I" toward the rear. Hope this help a little.
 

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Discussion Starter #6
Would it even start up installed the other way around? I put a new one in and it's starting and running fine. The terminals have no markings at all. I connected a tester to the positive terminal and the light lit up when I touched each other terminal on the solenoid, and also the hot wire to the distributor coil. I think I still have problems...
 

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Did you install the new solenoid up like the original or upside down like in your photo?
 

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Discussion Starter #8
The one in the photo was installed the same as the original. After it failed, I installed the new one the same way.
 

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Discussion Starter #9
Raghead, you were right on. I flipped it over, swapped the S and I connections, and it fired up on the second try. Starts up every time now. Is it possible I fried something inside since I had it backwards last time?
 
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