Need Help installing Disconnect bracket

Canton_Model_A's

Canton_Model_A's

Senior Member
Greetings Barn Members, need some help in attaching Snyder's disconnect switch bracket to the starter. Not sure how it goes in. Does anyone have a picture or a document to follow? Getting tired of disconnecting the battery each time.

Thanks!

Dave
 
Use any of the three bolts that mount the starter, whichever is most convenient for you. Mine mounts on the bottom bolt near the outside of the car but I have to lean under the car to turn it off and on. It is sort of hidden which means when it is off a would be thief would have a hard time finding it, but it is in an inconvenient location.
 
Mine is mounted on the starter.

The battery cable you see is connected one side of the switch.

The spiral cable allows me to shut the battery switch off from inside the cab, should there be a problem requiring immediate disconnect, otherwise I would have to open the hood to disconnect......
 

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Thanks for your comment!

I remember seeing a post some time ago of a CCPU parked and on fire due to an electrical short.

That prompted me to install the switch, as disconnecting a battery cable when parked or in storage just wasn't practical.

The spiral pull cable is there just in case. If you had smoke from the engine area the last thing you'd want to do would be to open the hood...

The side rail in the cab already had holes in it....there must have been something mounted there at one time.

Randy
 

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The switch in both of my Model A's uses the existing hole in the engine's mounting bracket.
 

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Dave,
I mounted the bracket to the bottom starter bolt. A new braided cable went from the disconnect switch up to the starter switch. I rerouted the existing negative cable from the starter switch down to the disconnect switch. I've had no problems with this setup.
Gary
 

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The only problem is that the switch should NEVER be on the hot side.Should always be on the ground side.
If you have a cable problem,or a switch problem,if the switch in on the ground side things just won't work.If it's on the hot side that live cable can make quite a lot of sparks.I've worked on equipment all my life,and Cat,International,JD,all put the switch on the ground side.I've seen a few failures of switches and cables,one spectacular one was in an A where the owner had put the switch on the firewall,and could switch it with his foot.The cable pulled out of the lug,and dropped down.It made weld marks around the engine compartment.If that had been the ground cable,it would have just quit.I have never heard a reason that would hold water to use the hot side.
 
Keith,
That makes sense, so I changed my disconnect switch setup today to work on the ground side of the battery.
Gary
 
Keith True said:
The only problem is that the switch should NEVER be on the hot side.Should always be on the ground side.
If you have a cable problem,or a switch problem,if the switch in on the ground side things just won't work.If it's on the hot side that live cable can make quite a lot of sparks.I've worked on equipment all my life,and Cat,International,JD,all put the switch on the ground side.I've seen a few failures of switches and cables,one spectacular one was in an A where the owner had put the switch on the firewall,and could switch it with his foot.The cable pulled out of the lug,and dropped down.It made weld marks around the engine compartment.If that had been the ground cable,it would have just quit.I have never heard a reason that would hold water to use the hot side.
Click to expand...

I am in total agreement with Keith. If I remember correctly there was a recent article in one of the national magazine where a Model A burned because the switch was on the negative cable going to the starter. The clutch rod wore thru the cable. They couldn't get the floor out fast enough to disconnect the positive cable.
 
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I did run into an interesting situation on one of mine a couple of weeks ago.My 31 Coupe has been turning a little slow for a couple of years,so I figured I'd look into it.I've always felt the starter cable was a little skinny,and figured that was the problem.The kill switch was off,and as I was sitting in the car I saw the ammeter move when I stepped on the brake.I hit the starter and got a couple of clicks and grunts.This was with the switch off.Cranking the starter with the switch on made the switch get real hot.I took it out and checked it,the switch was not only weak,it was passing juice to the switch body,or ground while cranking.Something was melted inside.If I'd had it hooked to the hot side,I would have found out real quick.Direct short.
 
1955cj5 your switch setup is great and it appears you are switching the (+) ground which is correct. I plan on using your clever idea on my "A's". On another note: My son's restoration business restores antique fire engines. These vehicles never originally included battery cutout switches. He always installs a battery cut out switch which typically gets mounted in locations that are not easily accessible. Your concept will be a nice quick disconnect solution.
 
I am beginning to understand the logic behind installing the battery cutout switch on the ground side.

Lets say that if you had a short so that a wire was getting hot enough to melt. It would not matter whether you had the switch on the hot side or the ground side, a quick shut off would keep the wire from setting the car on fire.

Now lets say that the wire from the hot side of the battery that goes to the switch gets chaffed and shorts out to something. Turning off the switch would not stop the short and there is the potential for disaster.

Now lets say that the switch is on the ground side and there is a short to ground in the wire leading from the ground side of the battery to the switch. You would never know it and there would be no detriment to the car. However, the battery switch would NOT function in the case of a short on the hot side because of the cable to the switch being grounded. The current to the short on the hot side would depend on how many amps the short on the ground side can carry.

So it appears that the switch on the ground side is maybe a little safer.

If you do have the switch on the hot side, make sure that there is no possibility of the heavy cable from the hot side of the battery to the switch from shorting out to ground, like from the clutch pedal chaffing through.

On my boat, shutting off the battery switch disconnected both sides of the battery, and this seems like the safest way to go.

Now if I can just understand the logic for other things in my life.
 
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CT Jack said:
1955cj5 your switch setup is great and it appears you are switching the (+) ground which is correct. I plan on using your clever idea on my "A's". On another note: My son's restoration business restores antique fire engines. These vehicles never originally included battery cutout switches. He always installs a battery cut out switch which typically gets mounted in locations that are not easily accessible. Your concept will be a nice quick disconnect solution.
Click to expand...

Thanks Jack.

I think with a little engineering a cable could be used to both disconnect and re-connect the battery, allowing the switch to be in hard to reach locations.

Randy
 
So, on the ground side how would the cables be run from the kill switch? What would all the wiring look like?
 
From the (+) positive side of the battery, one power cable runs to one post on the switch, from the other post on the switch a power cable runs to the mounting bolt on the starter.

The switch just interrupts the otherwise single continuous (+) positive ground cable.

My switch seems to be spring loaded internally. I think the external lever puts pressure on a contact that then snaps into the "on" position and is held there by the internal spring.

Maybe someone has taken one of these battery disconnect switches apart?

Randy
 

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