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Leif
'67 Coupe L79, M21, C60, N14, N40, J50, A31, U69, A01, QB1
Top Flight 2017 Lone Star Regional -
Re: 65 engine wiring harness short
My best guess as to the root cause was that the fiber insulating washer on the alternator was cracked that left the red wire short against the alternator causing the melt down?
DMK
33103Comment
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Re: 65 engine wiring harness short
Dave, Might I make a suggestion when you get all of your parts and new harness reinstalled....
On the starter solenoid Bat+ stud, before attaching the 10G Red(feed) wire to it, temporarily install a 15 AMP fuse in series. Use either a heavy duty alligator clip, or simply use a bolt to tie the fuse holder terminal to the feed wire, the other end of the fuse holder wire to the Bat+ stud on the starter solenoid. You'll have to add the terminals yourself, 3/8" diameter.(eg photos below showing smaller terminals)
In case there is some type of catastrophic short somewhere in the car, the fuse will protect the new harness. You cannot test the headlight motors or try to start the car as that will exceed the fuse rating.
On every C1/C2 restoration/body off I've ever done, I did that as a precaution. I never had a problem on power up but it was insurance. Well, I did have a problem once on a C1 when I dropped a screwdriver onto the VR and it shorted Bat+ to ground, but I had added that 30A fuse off of the main feed at the Ammeter as part of my normal process. Saved the day.
RichLast edited by Richard M.; December 22, 2022, 01:06 PM. Reason: Black feed not Red, nope, it is Red, but 10G not 12GComment
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Re: 65 engine wiring harness short
Rich,
Great idea. I'll rig a fusible link up and throw the knife edge switch once my wiring is complete. GM added fusible links to the later Corvettes to protect vulnerable electrical areas.
Thanks,
DaveComment
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Re: 65 engine wiring harness short
Dave, A Link would work, I'd suggest a 16 Gauge, but if there is a short, the fuse is easier to replace if it blows during testing.
RichComment
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Re: 65 engine wiring harness short
James right at the lighter and just tuck it up high.
Rich
PS
Edit- Here's a example under a '60.
fuses.jpgLast edited by Richard M.; December 23, 2022, 01:11 PM.Comment
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Re: 65 engine wiring harness short
Richard,
I installed the new LL engine harness. My pos battery cable is brown. The red/black cable and brown cable fasten to the solenoid main stud. My solenoid has two other smaller posts. Please more clearly describe the color of the wire or cables where the 15 A fuse is installed.
Regards,
Dave KComment
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Re: 65 engine wiring harness short
Dave,
Your Brown cable is Ground. Black cable is Positive. If you're using original type cables. See your LL Wiring diagram.
I'm tied up for a while but will get back soon with more info. Just wanted to let you know about Battery cable colors asap.Comment
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Re: 65 engine wiring harness short
Rich,
You are right. However, for the fuse in line from battery to starter, shouldn't this be 30 amp, not 15amp? 15 amp is for cigarette lighter.
DaveComment
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Re: 65 engine wiring harness short
Dave, Ok good, I got worried.
Back in post#18 I talked about adding a fuse just as a temporary operation, not a permanent solution. This would go between the heavy gauge Red wire which normally connects along with the Black(Positive) battery cable to the solenoid Main power stud.
I suggested a 15 Amp solely for the purpose of a power up basic test. You could then test all of your circuits except engine Crank, Headlight rollup motors, AC Clutch(if C60) or any other high power accessories like aftermarket AC or aftermarket high power radio AMP, etc.
When you first connect your battery knife switch(as I recall you said I think), if there is any miswire which could cause a direct power to ground short, that 15 Amp fuse will blow, likely saving your new harness.
Now after the power up test and if all is good, you could then remove the fuse and connect that heavy gauge Red wire directly to the Pos+ Battery stud on the solenoid with confidence.
If after the power up tests pass, you could replace the 15 Amp fuse with a 30 Amp fuse to test other functions, i.e. Crank, HL motors, etc. Just make sure the fuse holder is capable of at least a 30 Amp current draw.
Now for the long term, I have never used a 30 Amp fuse in a 1963-1966 Corvette for a permanent electrical safety feature. I have on the C1s with never a failure in normal running conditions, including my own '59 for many years, raining, wipers, heater, lights, etc all on.
You could try that in your '65 but I can't guarantee it would be a permanent solution. You'd have to experiment running, driving, heater on, wipers on, High beam lights on, rolling HL motors, etc. It may work but I'm uncertain in all conditions.
RichComment
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Re: 65 engine wiring harness short
My LL harness contains the red wire connected to a black wire with a ring connection that is fastened along with the black main pos battery cable at the solenoid main connection. The LL wiring diagram show the red and black wire connected together.
DaveComment
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Re: 65 engine wiring harness short
Rich,
Pictures of my red/black cableCable1.jpgCable1.jpgCable1.jpgComment
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Re: 65 engine wiring harness short
I can see your confusion, but this is just a cost savings... to tie 2 wires to the same terminal going to the same place.
The heavy gauge Red is tied together with the smaller gauge Black wire with the one 3/8" ring terminal. The Black wire is simply the source wire to the BATTERY gauge. The gauge needs 2 connections, one from the battery(source) the Black wire, and one from the Horn Relay Buss(load), Black/White wire. The gauge reads the difference of the 2 voltage points to show charge or discharge.
This is still where the temporary fuse goes, between that 3/8" ring terminal that has the Red/Black joined, and the solenoid stud. I did a quick markup of your LL diagram. Too bad they didn't color code it.
Horn1mod.jpgComment
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