Battery cut out switch on the old CASE

Greenfrog

Member
I want to put a switch in the battery cable for safety, that is, so there is no drain on the battery when it sits a lot, and when parked on display at the county fair so that some kid doesn’t pull the ignition switch on, hit starter, etc..
Which cable does the switch go on?
After research, there seems to be some discussion and disagreement on this!
I noticed old tractors having them on, but never examined which—positive or negative side??
 
When I googled it there was a lot of information, but they talked about + and -, and with an old tractor either could be ground, and I think ground is the preferred place to put the switch.
 
(quoted from post at 16:56:54 07/27/20) I don't know if it's right or wrong, but I've always put them on the ground cable side.

I would agree.

On a negative ground system with the positive switched.........
Switch mounted in sheet metal........
Terminals exposed......
Anything metal coming off, falling, rattling around near live positive terminal(s) would be asking for sparks.
 
If you can, use whichever cable goes to the frame. BUT in some applications you have to use whichever you can get to. I have one on the positive cable oo my '85 Monte Carlo, because I could not fit it on the negative side.

The idea of cutting the ground is then nowhere on the vehicle can the wiring find a short to ground.
 
On my SC CASE, the flat ground cable is barely exposed. The battery is under the gas tank, and the flat ground cable goes down to a bolt near the bottom of the battery. Just no room. Positive cable would be easy.
Please advise.
 
just unhook the flat ground cable why buy a sw when you just take a bolt out you buy a sw then there are two more places for a bad connection one bolt easy fix
 
Many older tractors came from the factory with 6 volt positive ground. If you don't have a 12 volt alternator on it, could you switch it back to positive ground?
 

It really makes no difference whether you put the disconnect on the + or - post ,, except for one fact,, and test me on this,, disconnect the neg cable at the battery (neg ground system or pos cable for pos ground), hook up a test light or volt meter ground lead to the the disconnected battery post, now turn on a headlight switch or turn on the ignition switch for points (closed points, or pertronix ignition) for a closed circuit, then touch your test light or volt meter lead anywhere on the tractor that is not painted or rusted, and note the result.
Now if you want the safest disconnect possible consider that your breakers in your house disconnect the positive power source,,,think about why!! :!:
 
I agree with you. Your answer explains it well. I think it should go on the positive cable. Then everything is off. After talking to other guys at antique tractor shows,
some stated that after these old tractors sit awhile, there seem to be a little drain on the battery, and eventually it goes weak or dead. That was the case I had on
another tractor. It was on a DC CASE. Upon putting the switch on the positive cable, that problem stopped.
 
Either side will work just fine.

WAY more important is that the top of the battery is kept free of dust, chaff, dirt and debris that will get damp and drain the battery even with a disconnect switch installed.
 
(quoted from post at 01:46:45 07/28/20) I want to put a switch in the battery cable for safety, that is, so there is no drain on the battery when it sits a lot, and when parked on display at the county fair so that some kid doesn t pull the ignition switch on, hit starter, etc..
Which cable does the switch go on?
After research, there seems to be some discussion and disagreement on this!
I noticed old tractors having them on, but never examined whichpositive or negative side??

Here is why it goes on the negative side.....FOR SAFETY.
With the cutoff on the positive side that you have installed, take a volt meter, and take a reading from the plus side of the battery to ground. You Will measure battery voltage.

If the plus side of the battery gets shorted to ground, they will be sparks.
If the negative cable is isolated from the frame with a switch,
There is no path to ground. Taking a volt meter from battery plus to ground you will measure no voltage, no sparks

Guido.
 
Several years ago I was going to put them on and it would have been on the hot cable from the battery and tractor was positive ground from factory so the darn switch was to fit wrong size battery post for a positive ground tractor and there was no room under hood for switch to fit to either cable. Gas fill was close to battery and with a steel funnel if not paying good attention you could hit the hot cable with the funnel and have a short but with the cuttoff built into the clamp that went on the battery post and cable fastenrd to that no way could you have a short by hitting the cable end on hot side but on ground cable you do that and you can still have the short. Hitting the hot cable on battery and funnel to battery ground. I would go for hot cable.
 

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