1960s Smoke pours out when new battery is hooked up

[Art Director]

1963 Six-Window Sedan de Ville

Just bought a new ACDelco battery from the Cadillac dealer in the nearest city. I should be using a Type 27 battery, but it's no longer made. So, I took a Type 56, the only battery available that will fit in the tray, albeit loosely.

I hooked it up with the negative cable first, then the positive cable. Immediately, smoke started pouring out of the area where the negative cable was hooked up. The cable was very hot to the touch. I quickly disconnected both cables and the smoke stopped.

This car has caught fire once before and it cost me a fortune to have restored despite insurance; I am not going to go through that again. What could have caused the cable to smoke the way it did? The car hasn't been driven in almost eight months.

[The Tassie Devil(le)]

G'day Tim,

Smoke escaping from anything electrical is usually attributed to Lucas Electrical components.

But, seriously, you should never connect the Negative cable first.   Always last.

As for the amount of smoke, sounds like you have a serious short.   

Was the ignition turned on at the time?   

Hopefully, someone with more knowledge than I in electrics will come to your rescue.

Bruce.

[Art Director]

Hi Bruce, never had a problem until now. I had always disconnected positive to cut down on battery drain.

No, the ignition was not turned on.

Tried it again, positive first, then negative. Same result. There has to be a short somewhere in the electrical system.

[The Tassie Devil(le)]

Tim,

First check would be to trace the Positive Cable to the Starter Motor terminal, making sure that there has been no compromise with the insulation being compromised, and shorting out on a clamp, bolt or anywhere along its' length.

Bruce.

[bcroe]

The method often used here, is connect your
battery neg.  Then use a 12V test lamp connected
between battery and car pos terminals.  With
nothing on it should not light, if it does
start disconnecting car 12V loads and wires
till it goes out.  good luck, Bruce Roe

[Art Director]

Thank you, two Bruces. I have the Shop Manual as well. I will need to get a 12V test lamp at the auto parts store.

I have also reached out in the nearest city to find a tech who works on old cars as I'm new to the area. My knowledge and my time are very limited.

[The Tassie Devil(le)]

For a test light, you don't need anything special.

What I use is an old single filament tail light or reversing light socket, and use the single wire from the socket, and solder a second wire to the lamp holder, with a tail the same length as the primary wire, and put a small alligator clamp on each end.   I wrap the socket with electrical tape to isolate the chances of accidentally grounding out the housing on a live feed.

This way you can hold one end to the battery terminal, and the other end to the battery clamp.

It is easier to use a simple filament lamp socket than a Stop/Tail lamp socket because the Stop/Tail Socket has an extra tail that you don't need.

Plus, it is easier to use an older cars' socket as it will be steel, as against plastic, which has a smaller separate grounding tab.

Bruce.

[Roger Zimmermann]

Bruce, when somebody has not a lot of time and few electrical knowledge, a test lamp from a store is the best! No need to solder or search for the needed material...Probably Tim will have the same opinion!
Anyway, no matter which post is installed first, that smoke and heat is the indication of a serious short somewhere.

[The Tassie Devil(le)]

You are right Roger.   I forget that I have a lot of old parts laying around from previous cars that I have stripped.   Plus, Tim has recently moved, so he might have tossed out a lot of "old" stuff.

Bruce.

[bcroe]

My test light has a big clip on one wire, and
a small clip on the other.  Usually one clip
fits where it needs to connect, the other I
probe with. 

Do use some kind of battery minder on that new
battery.  If it sits after you have run it down, it may
be permanently damaged.  good luck, Bruce Roe

[tcom2027]

What changed between the time you decided to replace the battery and and you changed it?

Assuming the electrical system was performing satisfactorily before you installed the new battery consider the following:

 Have you considered that the new battery may be shorted internally?

Grab a Known to be good battery, it doesn't have to be the "correct" battery just a stable 12v source, see what happens.

Positive off and on first. Always

If possible always disconnect the negative side to immobilize the electrical system.
.

[Big Fins]

Tim, the biggest reasoning for connecting the positive+ cable first is, there is no connection to ground. If you hook up the negative- first and then the positive+, while making the connection tight, your wrench could come in contact with another portion of metal surrounding the battery. If that happens, you'll have a chance of arc welding that wrench to the car, hard grounding the battery, which can short it out and possibly an explosion of the gasses emitted from the battery through the venting.

Always connect positive+ first, tighten the connection and then the negative- side. And when placing the negative- cable onto the post, try to make it a fast connection to avoid a spark when the connection comes in contact with the battery post.

That is also why you never wear any type of jewelry when working on autos. Any connection of a hot wire to ground through the ring/watch/bracelet and it's not going to be pretty.

But, if your getting smoke when you make the connection, you have a hard ground somewhere on the main circuit. I can't believe it's not sparking when you try to make the connection.

[tcom2027]

Good point about wrenches contacting battery terminals. Same for hydrogen gas when a battery is charged in a confined space. A battery explosion can be exciting. Sulfuric acid, even dilute, can damage your eyes, and plays hell with the paint on underhood components. I always blow or wave my hands over a battery before I try to remove a cable or go to hook , ect. to one. Can't hurt, may save your eyes.


FIfty plus years ago while working under a tractor with a 24v system, I had the battery cover off and a charger hooked, set on slow charge. I had left an extended length 15/16" wrench on the battery set. Needing it I reached up feeling for the wrench. I managed to get ahold of it just as the wrench found the positive and negative terminals. I grabbed the wrench and yowled as it contacted my wedding ring. I didn't feel any shock, only the heat generated by the short.  THe wrench stayed in contact with the terminals long enough create a lot of heat. It was a four six volt arrangement with a tangle of wires on top. My finger swelled up in spite of immediately jamming it into a snow bank. It was a bad burn. At its peak I could hardly see the ring. When the swelling went down a little I cut the ring off. As a result, I had a pretty good sized scar on my left ring finger. Haven't worn a wedding ring since.

After all this time I can still see a shadow of that scar on my finger. I Should have kept my glove on. Finished the day. For the next few days around the shop I was reminded not to do something like that again every time I bumped it.   

To reiterate, electricity, d/c or a/c even at low voltages an amperages can can injure you and it can happen quickly.

tony   



 

 

[Big Fins]

It takes less than 1 amp to kill a person. You can't let go.

[tcom2027]

True, the brain can only withstand 100 to 200aM to be deadly and 110/120 volts at 58-60 cycles will do it easily. It's a case where amperage, frequency, duration and resistance play a part.

DC current causes an involuntary convulsive muscle contraction that pushes the body part away. It's the intermittent nature of A/C that causes muscles to freeze on the source of the current.  With D/C you jump back when you short a spark plug wire or other D/C source. In the days before HEI a 6v coil condenser system typically generated around 10-12k volts at the plug. Our modern cars with coil packs can generate 60k or more. Shorting a coil pack while working on your 2022 XLR will definitely knock you back, and you'll be using your off arm to hoist a beer for a couple of hours. Obviously if you have a pacemaker, results may differ.

Way to much information, I know. Bad day in the shop. I was testing my '46 Chrysler for a head gasket leak and dropped the tester, the fan got it. Fluid and plastic all over the engine compartment.  2022 plastic just doesn't stand up to 70 plus year old Detroit produced steel spinning at 475rpm more or less. Time for a Sapphire and tonic. 

   

[TJ Hopland]

Whats the power distribution like on a 63?   Is it at the starter like it was later?

Any signs of any critters in the last 8 months?   Since it got rewired I wonder if it could have got some of that yummy European wiring that North American critters really seem to love?

Sounds like there are multiple problems now.  The smoking ground connection is apparently a weaker connection than wherever the actual issue is so there are at least 2 areas that are gonna need repairs. 

That ground connection can't be the problem because there should be very minimal load on it most of the time and especially with the key off so the fact it appeared to be smoking means there is a serious load somewhere that was overloading that ground connection.

[Art Director]

Well, guys, problem solved.

Seems that ACDelco, when they redesigned the looks of the battery, moved the terminal posts to the other side, on the short side. In other words, reverse polarity happened because I didn't pay attention to the plus and minus signs. Luckily nothing fried.

Turned the battery around, hooked it up positive first, then negative. No sparks, no smoke. Started up in less than two minutes.

Had a nice cruise today in the car, the first in almost nine months. Got some real gas (no ethanol) in it and it drove like it should. My CLC duties slack off this time of year, so I get the time to drive "Herb," named after the late CLC Central Regions VP Herb Karow.

Next, it needs an A/C recharge, but a professional has to do that since the system is still R-12. And the temperature gauge was jumping all over the place, especially when accelerating, but that's another time, another day. Thanks so much, guys. Fellow CLCers are the best!

[Art Director]

Whats the power distribution like on a 63?   Is it at the starter like it was later?

Any signs of any critters in the last 8 months?   Since it got rewired I wonder if it could have got some of that yummy European wiring that North American critters really seem to love?

1963 is the first year where Cadillac used an alternator rather than a generator, so I would imagine power distribution is at the starter.

No critters. I'm in a new home in the country where they haven't gotten in, at least yet.

[The Tassie Devil(le)]

Who'da thought that it was as simple as that.

Maybe you need new glasses?  

Bruce.

PS.  You are very lucky that noty more damage was done, especially to the charging system.

[Art Director]

Who'da thought that it was as simple as that.

Maybe you need new glasses?  

Bruce.

PS.  You are very lucky that not more damage was done, especially to the charging system.

Haw haw haw, Bruce. I didn't have my reading glasses on when I installed the battery, if that helps. 

When the sparks and smoke happened (less than one second in time), I wrote here right away for advice. But the cables look like they should be replaced anyway due to their age (13 years) and the fact they don't have a bolt and nut on the end to tighten them on the terminals. I had to squeeze both cable ends and use a hammer to lightly tap them on to each terminal.