Disconnect switch.

[captndan]

It seems there are many small electrical problems associated with an 85 year old car. And that's to be expected. Instead of tracking down small problems it would seem logical to just install a battery disconnect switch. So with that thinking where would the ideal place to put that switch on a 30 coupe? I don't see the amp rating of the switch so I don't know what size wire to use.

[H. L. Chauvin]

FWIW: Seriously,

1. "If" you look on this Forum under "Search", or on the Internet, you will receive enough varying information on Disconnect Switches to keep you busy reading for several months.

2. "If" you call about (3) Model A parts suppliers and ask which switch do they think is most "popular", after analysis with a "Poll", you will be at least (politically) (LOL) correct.

3. By the time all disconnect switch recommendations later swarm in below, you will be just as confused as after asking questions under 1. & 2. above.

Do not get discouraged ....... hurry up and choose one (1) ....... it is only about as complex as nominating someone for President in 2016 ...... and at our age, there is not much time left to ponder.

Hope this helps.

[Mitch//pa]

I wouldn't put in a disconnect switch to cure another problem... Personally i like to fix any electrical issues that are wrong IE draws etc etc:'. and use a disconnect for just that a disconnect....

[Brentwood Bob]

Surgery is preferable to a band aid.
Having said that, I have a cutoff on the floor
near the seat in the Huckster. To me, that is a good location.
In an emergency it doesn't take too long for a fire to start.
Bob

[Tiny]

http://www.snydersantiqueauto.com/disconnect-bracket
http://www.snydersantiqueauto.com/disconnect-switch

I like this set up. Just lift the hood reach in and turn it off.

[Jim M]

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FYI I have the one pictured above and it works great. I do not have any electrical leaks that I know of but this will make sure. For what it is worth I NEVER plan to put my car in any competition so I switched to negative ground so the cut off is on the positive wire. This insures the battery is disconnected from everything including the frame. Took me 5 minutes to change the wires on the coil and ammeter. Generator works just fine.

[OL JENNY]

You might want to consider placing the disconnect switch on the ground side of whatever type setup you have. If the engine is running and you have your disconnect switch on the hot side, the generator/alternator will probably allow the engine to continue even after turning the disconnect switch off. If the disconnect switch is on the ground side, if you turn it off it will kill a running engine. Mine is currently on my negative (hot side), but I am moving it and changing to the positive ground.

[H. L. Chauvin]

I have an installed El-Cheapo red & black plastic disconnect switch with removable red plastic red key on my 1947 Farmall Cub tractor ..... first same type cheap disconnect switch got corroded and quit working ......

The Cub's old starter switch, (similar to a Model A starter switch with starter rod), got stuck, thus continually making contact.

The electrical heat generated ignited the old oil and grease on the starter, which is located directly "under" the gas tank and under the glass fuel sediment bowl.

Flames were hitting the underside of the gas tank .... tractor was parked a few feet from wood siding house.

When switch was turned, disconnect switch disconnected the ground wire near the remotely located battery ....... flames subsided immediately.

Once in a lifetime disconnect safety experience ...... gas tank did not explode ..... house saved ..... I'm still living ...... but each to his own ...... just driving on any highway is a risk we take.

[captndan]

I am certainly glad you and your Cub survived.
Actually I did a search of several places and came up with nothing. No specs. The leak problem is in the turn signal switch. Otherwise the switch works fine. My thinking is that I can install the cutoff switch cheaper than replacing the turn signal. Solve one problem and maybe prevent another one. I like the Snyder's idea and will probably go that route. I also agree that a band-aide on a battleship don't get it. Thanks for all the ideas. Dan
BTW I have two Cubs, an SA, an H, and an M.

[Tom Wesenberg]

I never expect electrical problems as long as I know the wiring is good and I have gone through all the electrical items. I don't use a master disconnect nor a fuse, just to stay more original. My battery cable is just pushed on the battery post and I can lift it off quickly if I have to.

I worked on a 31 original popout that had a slight drain in it. Once I got the switch out of the housing I found a lot of graphite inside. I removed it and the drain way gone. I usually use a drop or two of ATF for lubricating my switches. I used graphite on my 99 Olds, which was getting very tight last winter. A couple puffs of graphite and it freed right up.

[Patrick L.]

The Model A is very simple. I too recommend fixing any problems, then add the main cut-off if you want to.

Its probably best to install a good quality main switch in the ground line, but, I don't think its a necessity. I'm a fan of adding an extra ground lead [ 1 or 0 gauge] from the frame to the transmitter or bellhousing.

What signal switch are you using. It shouldn't draw. Signal-stats are famous for being super packed with grease and removing most of it solves the problems. Also its best to add a ground line to the mounting clamp.

[C26Pinelake]

Originally Posted by Brentwood Bob

Surgery is preferable to a band aid.
Having said that, I have a cutoff on the floor
near the seat in the Huckster. To me, that is a good location.
In an emergency it doesn't take too long for a fire to start.
Bob

Great logic Bob ! I agree with all points you made! Wayne

[sethkestenbaum]

I've got a switch and sleep better at night knowing that I use it. It is also very handy for me, as I can "disconnect" the battery without having to remove floorboards. I also see it as an extra layer of security for the car. If I leave the car parked and open, folks tempted to reach in and honk the horn or turn on the lights get no reward for their efforts.

My switch is under my left foot in the car. I did have to cut a hole in the floorboard.

[H. L. Chauvin]

FWIW:

On my 1930 Town Sedan, have "keyed", heavy duty, Marine Rated, Metal Disconnect Switch, with removable key, disconnecting the (+) ground battery cable for past (6) years or so ..... and like with many, disconnect switch is accessed through steel chassis cross rail opening with round access hole cut in floor board, hidden by carpet floor mat.

I only disconnect the battery ground cable with this switch & remove key if I park in a public parking lot and leave car unattended.

I used this disconnect switch often when I entirely rewired the entire car.

When parked in a locked garage in a rural area at home, the ground wire stays connected all of the time.

In my opinion, depending on local garage conditions, public parking lot conditions, current electrical conditions, estimated precautions felt necessary, just do what one thinks is best for their situation and smile.

[mshmodela]

Yes put the best switch you can find --fires are no fun.. I recall the sound when I was 14 and the man 2 homes down made likely one of his last sounds durning a barn fire... It's a sound and memory I wish I could forget...

[katy]

If the engine is running and you have your disconnect switch on the hot side, the generator/alternator will probably allow the engine to continue even after turning the disconnect switch off. If the disconnect switch is on the ground side, if you turn it off it will kill a running engine.

I don't believe that. Methinks that even w/the disconnect on the ground side the engine will still run when the disconnect is opened. Don't forget that the generator or alternator has 2 sides to it, the output and the ground.

[duke36]

See the threads from a couple of days ago re;switches. The Cole Hersee website has product info. for Master Disconnect switches.Some have long shafts and for example, 1000 amp non-contin. ratings, 6-36 volts.. These switches are similar if not the same products as the A vendors sell and have been reliable for me. The sales dep't. can help on selection. As mentioned, you may want to select something to accommodate cranking amps of the battery used, with heavier gauge wire for 6 volt.

[Fred S]

Originally Posted by katy

I don't believe that. Methinks that even w/the disconnect on the ground side the engine will still run when the disconnect is opened.

I agree. My disconnect is on the ground side, and my engine will continue to run if I turn the disconnect off.

[Bob Bidonde]

Battery disconnect switch installation I typically use in my Model A's. The switch is in the driver's side engine mount and just in front of the battery. No modifications to the frame or body are necessary.