NorCam
06-06-2020, 05:06 PM
I have an electrical issue with my 69 Z after just going through the entire car and freshening it up with a thorough cleaning. The car has its untouched original harness throughout and it just experienced a dead short while it was parked after a road test? There are no cuts or splices anywhere to be found and no broken wires that I can see going to ground. Whatever caused this dead short occurred right after it was parked from a short cruise just the other day. Ignition was turned off and the car sat there with me standing right in front of it when I heard a snap which was immediately followed by a high current meltdown.
It quickly fried the 20" fusible link between the + battery terminal and the + distribution block on the rad support. I immediately grabbed a wrench and pulled the ground then the positive cable and surveyed the damage which claimed the fusible link. The link was draped around the lower front corner of the battery and the link became so hot that it melted through the corner of the battery case which caused the battery to leak some acid into the tray as well. In hindsight, it now has me wondering if maybe the wire got pinched between the battery and the rad support but never thought to check that before I yanked the battery out due to it leaking and me rushing to get it out of there after the fact.
The only things recently changed on the car that could perhaps be suspect would be a restored 367 Starter with a new solenoid, or perhaps a used 837 Alternator in original unrestored condition. It was tested as charging before it was installed. Those are the only 2 items that I can point to that have live power going to them while the car is switched off, hence my curiosity if one of them could be the culprit to a dead short if not the link being pinched? I suppose it could also point to the voltage regulator since power routes through it? I have since looked to see if perhaps that fusible link could have been pinched between the battery and the rad support but can't see any spots where it arced or welded to metal? Don't know for sure but have traced the remaining wires which all look sound and have the original wraps on them with no evidence of any trouble spots?
I have ordered a repro battery cable but still, need to isolate the cause of this short before reconnecting anything or putting a new battery in it. I would appreciate any pointers from any electrical guru's to help chase down the cause or perhaps the most effective way to test the lines and or possible hardware that may be at fault? Any ideas or things I could be overlooking?
Feel free to reply, PM, or call me on my cell for any tips or suggestions.
Thanks in advance.
Graeme
403-669-4035
https://i.ibb.co/rv6ZBLL/IMG-0797.jpg
The fusible link after it melted down. It saw high current and fried in seconds (big cloud of white smoke)!
https://i.ibb.co/NsqrRj7/IMG-0798.jpg
Where it appears to have started? Measures to the rust mark you see top right where it may have been pinched behind the corner of the battery?
https://i.ibb.co/7nJD9LT/IMG-0799.jpg
The side of the battery where it was scorched by the wire (top right to lower left) that was draped along side of it.
https://i.ibb.co/xYLq1XV/IMG-0830.jpg
Result of a very hot wire wrapped around the battery and melting through the case.
It quickly fried the 20" fusible link between the + battery terminal and the + distribution block on the rad support. I immediately grabbed a wrench and pulled the ground then the positive cable and surveyed the damage which claimed the fusible link. The link was draped around the lower front corner of the battery and the link became so hot that it melted through the corner of the battery case which caused the battery to leak some acid into the tray as well. In hindsight, it now has me wondering if maybe the wire got pinched between the battery and the rad support but never thought to check that before I yanked the battery out due to it leaking and me rushing to get it out of there after the fact.
The only things recently changed on the car that could perhaps be suspect would be a restored 367 Starter with a new solenoid, or perhaps a used 837 Alternator in original unrestored condition. It was tested as charging before it was installed. Those are the only 2 items that I can point to that have live power going to them while the car is switched off, hence my curiosity if one of them could be the culprit to a dead short if not the link being pinched? I suppose it could also point to the voltage regulator since power routes through it? I have since looked to see if perhaps that fusible link could have been pinched between the battery and the rad support but can't see any spots where it arced or welded to metal? Don't know for sure but have traced the remaining wires which all look sound and have the original wraps on them with no evidence of any trouble spots?
I have ordered a repro battery cable but still, need to isolate the cause of this short before reconnecting anything or putting a new battery in it. I would appreciate any pointers from any electrical guru's to help chase down the cause or perhaps the most effective way to test the lines and or possible hardware that may be at fault? Any ideas or things I could be overlooking?
Feel free to reply, PM, or call me on my cell for any tips or suggestions.
Thanks in advance.
Graeme
403-669-4035
https://i.ibb.co/rv6ZBLL/IMG-0797.jpg
The fusible link after it melted down. It saw high current and fried in seconds (big cloud of white smoke)!
https://i.ibb.co/NsqrRj7/IMG-0798.jpg
Where it appears to have started? Measures to the rust mark you see top right where it may have been pinched behind the corner of the battery?
https://i.ibb.co/7nJD9LT/IMG-0799.jpg
The side of the battery where it was scorched by the wire (top right to lower left) that was draped along side of it.
https://i.ibb.co/xYLq1XV/IMG-0830.jpg
Result of a very hot wire wrapped around the battery and melting through the case.