Okay...I've neglected my 67 coupe for too long and want to get back into driving it at least once a week. It's sat in my garage covered for over 9 months now. I have an electrical problem and haven't had the time to investigate it. Here's the events that led me to now...Number one culprit was that I got married and had two kids = no time for Mustang (my first love). However, when it was my daily driver I installed a quick battery disconnect, utilizing the small amp fuse to maintain my radio presets / clock. Once new cars were purchased, the Mustang rarely was driven. I turned the disconnect off, but made the mistake of not removing the fuse, thus as it sat in the garage over time, it slowly drained my battery. I was always puzzled by me having to jump it after 3-4 weeks went by with no use. Then a buddy of mine gave me a new two channel amplifier for which he had no use. I didn't either, but then realized the one in the Mustang was pretty old and not that great. I then swapped it out. Went to jump the Mustang to get it going, which became normal for me. No use, the battery was dead. I charged it, but it just wouldn't hold. I then went to buy a new battery and must have had my head up my butt because I accidentally reversed the postive and negative terminals when installing the new battery. Immediately smoke was coming off the wires leading up to the solenoid. I removed them promptly. I then discovered that the insulation on most of the wires in that area had melted / burned off. I then retraced each cable and rewrapped each one with electrical tape as far as I could find. Both fuses in my amps had blown as well.

So now I can't keep my battery charged and I can't keep buying new batteries. I must have a short somewhere and I'm afraid it's a needle in a haystack. Did I not rewrap one of the cables good enough, did I destroy the battery, damage something else, is the new amp faulty, solenoid fried as well, alternator coincidentally died of age? Where to start? Any suggestions on an ideal order for me to start eliminating culprits is very much appreciated. I would consider myself a step above a newbie at one time, but I've now had about a ten year absence from scraping my knuckles on this beast. Thank you!!

 

replace the loom that smoked. You might have fried the voltage regulator so the battery isnt taking a charge,but you wont know that till you get a voltmeter and test the output of the alternator.It should be at about 14-14.5V at about 1500 rpm.The battery at rest should be about 12.5 V. From there you can check for a current draw.

 

Unhook the hot lead that goes to the altenator. Lightly touch the lead back to the post you took it off of. Look for a tiny spark, like a static shock. If you see the spark, you have a bad diode in your alternator that is draining the battery. Happens all the time on our stationary diesels.

 

You prob did damage to the alternator's diode's and definatly fried the regulator (pass inside rad support). Its a cheap and easy swap out.

 

You either have a charging problem or a current drain. To keep from chasing your tail split it in two, and as said, check for 14.5v or so while the car is running. Look for a high AC component on the 14.5vdc. If it's in spec the problem is a drain, if not the problem is in the charging circuit. If it turns out you fried the voltage regulator spring for the few extra bucks and install an electronic one. Napa carries them.

This might help. 1967 Mustang Wiring and Vacuum Diagrams

 

as above for faults, but if you don't drive the car often use the battery disconnect without any bypass wires. The small draw from a radio over long period is what killing batteries. disconnect everything if you have to park up

 

Thanks for all the advice. I hope to jump on this soon and will post back the results.

 

I've replaced my battery, got a new voltage regulator, solenoid (probably didn't need one) and bought a voltage meter. All is great so far, but I'm working with a brand new battery. The voltage meter states the alternator is good too while running. I'm hoping one of those things fixed it. I guess I'll know soon enough. Thanks for all the input!