Ok - so I have a '68, with a 350. The car recently started doing some odd stuff. Not sure what is related, but here goes:

The horn would honk randomly - even when the car was parked and key was out! It wouldn't just "honk honk", but more like a whine/moan coming from the horn. Finally I just disconnected the horn (at the horns).

Then the battery (brand new) would die after parking the car for a few days. I'd charge it up, and be able to drive off. Didn't always happen - but I figured it had to do with the horn circuit - as maybe it was still "shorting" (?) and though the horn wasn't connected, it was still draining the battery somehow.

Then one day I went to start the car, and just heard a loud "CLICK!", and my interior lights went out. The car didn't turn over - it just fried the battery. I charged it up again, and the same result. Zap. I left the charger plugged in to it (plugged in to the wall outlet) and tried again "Zap Zap Zap Zap" - it wasn't a good sound, and the car was *not* turning over at all. (almost fried my battery charger in the process!)

So... someone came over, I charged the battery up, and they jumped the solenoid. Loud click (as before), and dead battery. Now - I have a solenoid mounted to the firewall, on the passenger side - not sure why. It looks like I might have one bolted to my starter as well. (the car is in the street, and there's traffic - plus it's a little chilly out to be crawling around under the car in the road)

Ok - so how do I fix this?! I was thinking of having the car towed to a shop (at random, I don't know any offhand) and having them replace the starter. Would that fix it? Other ideas?

Thanks!!!

ps - As an aside, my wife and I are expecting our first this February!!! Woohoo! Now I need to get the car started so I can move it out of the road, and at least store it in the garage. Plus we're planning on moving this spring, so I'd need to move the car a few more times.

I am not sure about the 2nd issue but I'm willing to bet the horn problem was the contacts on the horn relay on radiator support being closed all the time. Did you hear a bunch of clicking? Anyway, the circuit was closed and disconnecting the horns did not stop the circuit and that drained the battery.

Did you recently do anything to the horn relay? I found that if you accidentally reverse the 2 black power wires to it (because they look the same) the relay starts clicking away without pushing the horn button. Or possibly the relay went bad?

And congrats to you and your wife.

Check your positive cable from the battery, and make sure it doesn't have contact with exhaust, or any other metal.. -

The solenoid on your firewall is an external starter solenoid. -what it does is the same as the original solenoid on the starter, but it is not affected by the heat from exhaust.. -I suspect that whoever changed the original wiring on your starter, might have messed up with the job..

sounds to me like you got a short somewhere...a bare piece wire/cable that is grounding out.... , follow every wire ,make sure they are insulated from the body...I think somewhere it has kinked or worn thru , maybe at some place it goes thru a hole in the metal...

If the horn switch is closed for some reason, you would still have current through the coil in your horn relay. Diconnecting the horns just stopped the noise and the current flow through the horns themselves.

It sounds like you have a wire grounding out,I'd look
around the core support, if the horn is moaning it
likely the power is back feeding through the ground.

I did get clicking sounds at times which I figured was a horn relay, but I didn't go looking for it. Must have gone bad - I haven't touched it. Will disconnect that when I find it.

As for the short for the starting problem - the car's accessories work when the key is in the "on" position with no problem. As soon as you click it to "start" or if you jump the external solenoid, it shorts out. That should limit the amount of areas that could be shorting, right?

Could the starter be shorting out inside itself??

Yes, a starter can short internally. And a relay can short internally or externally, in this case more likely externally.

Check your firewall mounted solenoid and see if it heats up excessively. It should get warm, but not scalding hot, when you tap the key (yeah, I know, it'll kill the battery). So before you do the power test, look very carefully at the heavy gauge wire between the firewall mounted solenoid and the starter, and find the spot where the insulation is through and it is arcing to the block or exhaust or subframe.