Battery cable maintainance?

[Tom L.]

My '72 LS-5 has been sitting through the northeast weather for a while. This past sunday was the first reasonable day to go for a ride. I started it, drove for about an hour, then stopped for about 5-10 minuites. When trying to start it...NOTHING! Thinking it was heat soaked I patiently waited until the temp guage dropped to about 140 degrees (it was at 220 degrees). Still no luck.

I humbly asked a passerby for a jump, it instantly started and ran. I got home and used my load tester to load the battery...checked out OK. Then re-started it to be sure the alternator was charging...14.3v.

It seems that it must be the starter or the cables/grounds.

Here are my questions...
1. How well do stock cables stand the test of time? Should they be replaced or can they be trimmed and new ends added? (I have always soldered the ends onto new "home made" cables)

2. Is there a way to bench test a started without tearing it down?

Any help will be appreciated. Thanks in advance!

[Patrick H.]

Re: Battery cable maintainance?

Do you have a green knob battery disconnect? If so, you've found a likely cause. If you don't, then...

The first thing I'd do is check all the cables. This means the two at the battery, the positive cable at the starter, the ground below the battery where it attaches to the frame, and the ground cable running from engine block to frame at the right hand engine mount area.

If you check all of these, and they are tight with no corrosion, then check along each of them for major cuts. My 72 went dead from an age-old cut that eventually corroded the cable to nothing.

If all of that checks out, then check your connector at the firewall below your master cylinder. It may be loose, or you may have corrosion between the external and internal portions of your wiring harness.

If all of that was fine, then report back.

Patrick

[Tom L.]

Re: Battery cable maintainance?

Pat,
I do not have a disconnect , and I did a visual check of everything and saw no obvious signs of decay or damage. Everything was tight when "wiggled" by hand but I didn't get a chance to remove/clean each connection.

One thing I did not mention earlier, the starter support brace is missing, is it an integral part of grounding or simply support?

And...I didn't check the plug under the master but was wondering what that may cause? That plug is primarily for accessory and control right? Everything functioned, there just didn't seem to be enough juice getting to the starter OR the starter is bad.
Thanks!

[Terry M.]

Re: Battery cable maintainance?

The bulkhead connector also carries the ignition and control circuits. It is how the power gets from the ignition switch (inside the cabin) to the starter in the engine compartment.

No the starter brace does not provide a ground path, but without it the starter can twist and cause connection issues between the solenoid on the top of the starter and the starter body.

There is a ground wire at the starter that attaches to one of the starter attaching bolts. If broken, or attached to the 12-volt positive lead, this can create all kinds of unusual electrical problems. Check that out.

Lastly -- Patrick's car visually looked fine before we started moving the battery terminals around and found what you see in the picture above. Troubleshooting was easier because the car was on the lift at a meet when the failure occurred. One should put a wrench on ALL the battery wire connections -- both ends -- to be sure they are tight and NOT corroded. At the battery end one has to disconnect the side terminals in order to see the contact surface. They can be corroded and not show any outward signs.

One of my driver cars stopped dead in its tracks due to corrosion on the positive battery terminal. None of the corrosion was visible until the battery wire was removed. Side terminal batteries are very good at hiding the corrosion.

[Bill M.]

Re: Battery cable maintainance?

Lynn:

I had this problem about 1980 with my '65. It was corrosion of the positive battery terminal at the battery. Part of my annual maintenance routine is to remove the battery cables at the battery and clean until the posts and cables shine. No problems since.

Bill

[William C.]

Re: Battery cable maintainance?

Keep in mind the original Battery cables in that era were of a copper-clad aluminum conductor construction. This consists of an aluminum conductor sheathed with a thin layer of Copper for protection from the elements. At the terminal crimp area, a coating of solder was applied over the terminal and crimp area to keep the elements such as road salt out. If you live in an area where the car has been exposed to Salt on the roads, over time the protective solder will be eaten away and the probability of corrosion on the ground terminal is magnified greatly. The corrosion process is such that it will eat out the aluminum center leaving just the hollow copper tubes in the terminal. Well worth checking where the ground attaches to the frame on any of the 70's Corvettes.

[Tom L.]

Re: Battery cable maintainance?

William, excellent info. I was not aware that the wires were aluminum/copper clad. Is the copper coating significant enough to solder to? In the past I have always soldered new connectors onto wires as a repair/upgrade to insure a good contact and never had a problem. If I find that the wires are actually the problem this would be my preferred route. Especially when considering how involved changing the positive wire is! Thanks!

[William C.]

Re: Battery cable maintainance?

The cables will have the words "copper clad aluminum" printed along the outside jacket of the cable. The copper cladding can be soldered but likely not with a home based process. As manufactured, the ends of the cables were actually Dipped into a pot of molten solder to seal off the aluminum ends. Once the aluminum center is gone, the system cannot be soldered to any real effect. I'm not sure of the exact yours the product was used, Texas Instruments had a patent on the core and we Purchased it from them in rod form then drew it down and produced the finished product in-house (Packard Electric Div). I transferred into Engineering in '80 and it was in use then, and my '72 3-star car used it so it ran at last thru the 70's. I believe it was phased out at some time, but uncertain as to when. I don't believe it was on my C-4 in '83, but my memory is a little weak from that time. Maybe some of the C-4 folks can check and chime in. The printing on the outside of the cable jacket is in white ink and was always on the cable when the clad conductor was used.

[Terry M.]

Re: Battery cable maintainance?

You got the start year right Bill, although there was a report of a test batch of copper-clad aluminum cables for Corvettes in 1969 -- we have not seen them on 1969s in judging.

When I did the story on SST (Sealed Side Terminal) batteries for The Restorer, back when, Norm Uhler (who was the liaison from Packard to Chevrolet) wrote a companion article about the introduction of the SST. He mentioned the copper-clad aluminum cables and the 1969 test batch. I have often wondered if that test was really done on Chevelles, since they also got the early SST, but Norm's recollection was for Corvette.

[Patrick H.]

Re: Battery cable maintainance?

Pat,
I do not have a disconnect , and I did a visual check of everything and saw no obvious signs of decay or damage. Everything was tight when "wiggled" by hand but I didn't get a chance to remove/clean each connection.

One thing I did not mention earlier, the starter support brace is missing, is it an integral part of grounding or simply support?

And...I didn't check the plug under the master but was wondering what that may cause? That plug is primarily for accessory and control right? Everything functioned, there just didn't seem to be enough juice getting to the starter OR the starter is bad.
Thanks!

See the picture of the bulkhead connector in the "71 clutch safety switch" thread.

[Paul O.]

Re: Battery cable maintainance?

Lynn one simple check of your cables disconnect your coil wire to distributor cap to ground so the engine does not start. Then have someone crank your engine for say 20 seconds as they are cranking feel the positive and negative cables if one of them are getting very hot there is your bad cable. If there is any high resistance in the cables it acts like a oven heating coil. Paul 18046