Making the Case for a Battery Disconnect

[Norm B.]

Today after messing around under the instrument cluster my '63 coupe would not keep running once I released the key from the start position. First thing I checked was the ballast resister but it had continuity so I then looked at the ignition switch. Even though I have had the cluster out of the car 2 or 3 times I had never noticed the "Bubba" repair to the Ignition wire leading to the switch, see the first picture. I could not get at these wires properly without removing the cluster so it was another "Here we go again" job. For some reason, when I was removing the oil pressure line from the back of the gauge I looked up and to my horror discovered what you see in the second picture . Surprisingly I have never had any real electrical problems with this car in the 30+ years I have owned it. I thought I would post this as a reminder to everyone that whenever you are into any wiring or expose any wiring that you don't normally see to really take a few minutes and thoroughly check for this type of problem. This was just sitting on the brace under the dash and wasn't even really rubbing, see the third picture, so I guess it was just 50+ years of vibration. After 50 years even the slightest rubbing of wires can lead to a major short. Needless to say the battery disconnect switch just may have saved me. If you don't have one, get one.

[Duke W.]

Re: Making the Case for a Battery Disconnect

Good eye! Any car at 15 years and over 100K miles can develop electrical gremlins. Connector corrosion is common, and I know of one failure that is actually designed in.

Back in the early to mid nineties Mercedes got a bit too overzealous about recycleability of their cars and designed an engine wiring harnes that was "biodegradeable". Add 15 years of engine heat and most owers had to replace the harness due to disintegration of the insulation material, which costs about a thousand bucks for the harness, plus labor.

Fortunately, early Corvette electrical systems are simple and appear to be fairly robust, but after up to 50-60 years of service, one can never be too cautious. Certainly the designers never imagined that some of their products would still be on the road after a half-century or more service.

Duke

[Ron S.]

Re: Making the Case for a Battery Disconnect

That is a great reminder for these cars. One of my upcoming winter "to do's" will be the underdash wiring harness replacement, since it is approaching 51 years old! Plus the battery turn off too.

[Edward J.]

Re: Making the Case for a Battery Disconnect

Norm almost looks as though the mice or other critter has chewed through the harness? They can be a real problem on vintage cars.

[Norm B.]

Re: Making the Case for a Battery Disconnect

Norm almost looks as though the mice or other critter has chewed through the harness? They can be a real problem on vintage cars.

That's what I thought at first too but there is no evidence of mice anywhere else in the car or garage. I have been real lucky so far with no mice, chipmunks, squirrels, etc. probably due to my wife's love of cats that can access the garage. I turned the wire bundle 90 degrees for the picture, it was actually resting on the metal brace and you can see where it was touching.

[Timothy B.]

Re: Making the Case for a Battery Disconnect

Norm,

I would trace that wire in the diagram and see where it starts and stops. FWIW, give some thought to heat damage in that circuit that could have caused what looks like a rub through.

[Norm B.]

Re: Making the Case for a Battery Disconnect

Norm,

I would trace that wire in the diagram and see where it starts and stops. FWIW, give some thought to heat damage in that circuit that could have caused what looks like a rub through.

I agree. Now that I have it apart I am going to spend some time going over everything that is under there. Hopefully once I get the bundle unwrapped I will be able to see enough of the color coding to start a logical tracing of wires. Like I said earlier though, I have never had any electrical issues on this car in 30+ years.