CONNECTING A Electrical Disconnect Switch

[Cape Codder]

Today I want to connect an Electrical Disconnect Switch.

I am still unsure as to the correct hookup of a Electrical Disconnect Switch or Battery switch. I read in Brattons catalog to connect to the Negative Post on the battery from the switch while Snyders indicates connect with no indication as to what post of battery. I have also heard from friends to connect to the Postive Post of the battery. I have also been told that connecting it the wrong way will not cut off power to all of the car.

My question is which post should I connect to the Electrical Disconnect Switch to accomplish cutting off power to all of the car?

Thanks for your time.

[Y-Blockhead]

Originally Posted by Cape Codder

Today I want to connect an Electrical Disconnect Switch.

I am still unsure as to the correct hookup of a Electrical Disconnect Switch or Battery switch. I read in Brattons catalog to connect to the Negative Post on the battery from the switch while Snyders indicates connect with no indication as to what post of battery. I have also heard from friends to connect to the Postive Post of the battery.
My question is which post should I connect to the Electrical Disconnect Switch to accomplish cutting off power to all of the car?

Thanks for your time.

I can see why you're confused. To make it easy I like to install it on the ground wire, be it, positive (+) ground or negative (-) ground, whichever your car is.

Originally Posted by Cape Codder

I have also been told that connecting it the wrong way will not cut off power to all of the car.

Whoever told you that doesn't know what they are talking about. When you break a connection in any circuit it will cut the power...

[katy]

It depends on if your car is positive ground or negative ground. the switch goes inline with the cable going from the battery to ground.

[BillCNC]

It doesn't matter. Separating the connection of either one of those cables will cut off all power.

Sent from my SM-G920T using Tapatalk

[Cape Codder]

The car is Positive Ground

[Jim/GA]

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Install the switch in either battery cable and it will turn off all power from the battery while the car is parked.

There is a bracket sold that puts the big master switch down by the starter motor using one starter mounting bolt. When installed there, it is easy to connect the master switch into the cable that runs from the starter switch back to the battery. Everything is close to that location.

The original battery cable goes to the master switch. They sell a second cable (with eyes on both ends) that then connects between the master switch and the starter switch. Make all of these connections with the ground cable disconnected! Then the ground cable is the last thing that you hook back up, after all other work is complete.

There are many other ways to connect a master switch. I won't imply that this is the only right way to do it. But the above approach is easy and requires no permanent modifications to the car body, the frame, etc. It can all be easily removed and returned to original, if one wanted to do that.

[cpf240]

As I see it, there are two main reasons for putting the disconnect switch on the ground side of the battery.

1) If the disconnect switch is off, and you happen to drop your wrench on the battery tray and it contacts the frame of the vehicle and the non-switched post, no short circuit occurs.

2) If one of the cables to the disconnect switch rubs on the frame somewhere, and the wires contact the frame, no short circuit occurs.

[SeaSlugs]

Originally Posted by cpf240

As I see it, there are two main reasons for putting the disconnect switch on the ground side of the battery.

1) If the disconnect switch is off, and you happen to drop your wrench on the battery tray and it contacts the frame of the vehicle and the non-switched post, no short circuit occurs.

2) If one of the cables to the disconnect switch rubs on the frame somewhere, and the wires contact the frame, no short circuit occurs.

agreed.

[bbrocksr]

Originally Posted by BillCNC

It doesn't matter. Separating the connection of either one of those cables will cut off all power.

Sent from my SM-G920T using Tapatalk

It does matter!
If you put it in theHot/ungrounded cable the hot post of the battery and the cable to the switch will still be hot with the switch off.

If you put it in the ground cable nothing is hot with the switch off.

Bill

[Roadster62]

This is the reason most cars don't see the road, or are sold to others. NOBODY agrees to how wires should be run.


Bob

[BILL WILLIAMSON]

Either way round, Ol' Chap.
Bill W.

[George Miller]

If you mount it at the starter and you disconnect the starter cable, it can still short out on the brake pedal arm where it likes to rub. The ground disconnected stops that problem.

[wmws]

I agree with bbrocksr post #9. But if you don't care about that part of the cable from the hot post to the switch being hot even with the switch off then either cable is ok. But the only way for everything to be off is put the switch in the ground wire.

[bbrocksr]

Originally Posted by Roadster62

This is the reason most cars don't see the road, or are sold to others. NOBODY agrees to how wires should be run.


Bob

Really? Most cars aren't finished because of wiring disagreements?

Bill

[Crankster]

To further complicate things exactly what type of electrical disconnect is under discussion? It may not matter with lower ampere requirements but I've heard bad things about the type with the big green knob on it that are commonly available. They interfere with good current transfer.

[Bill G]

Here is a no "for-or-against" argument, at least from the electrical standpoint:

Every time you stop the car, pull out the floorboards and disconnect the battery and take it out of the car. That will insure everything is turned off.

Weighing in on the matter at least to me: Electrically, it doesn't matter. Switching it off does just that. It switches it off. The location of the switch and the resulting routing of the wires are probably the most relevant factors in determining which side you switch. Other than that it's preference.

[bbrocksr]

Originally Posted by Magicbox51

Here is a no "for-or-against" argument, at least from the electrical standpoint:

Every time you stop the car, pull out the floorboards and disconnect the battery and take it out of the car. That will insure everything is turned off.

Weighing in on the matter at least to me: Electrically, it doesn't matter. Switching it off does just that. It switches it off. The location of the switch and the resulting routing of the wires are probably the most relevant factors in determining which side you switch. Other than that it's preference.

When you disconnect the battery which terminal do you disconnect first to prevent arcing your wrench?

Bill

[Bill G]

Originally Posted by bbrocksr

When you disconnect the battery which terminal do you disconnect first to prevent arcing your wrench?

Bill

Granted, the best practice is to disconnect the ground first so that when you undo the "hot", you don't have to be careful to not touch the wrench to ground, but that is a different discussion than a battery disconnect. I would also add that in any modern car, the hot side is switched, not the ground.

-(Other) Bill

[wmws]

I will say it again, the only way for everything to be off is put the switch in the ground wire. If you put the switch in the hot wire, that portion of the hot wire from the battery post to the switch will always be hot.

[Mike V. Florida]

Originally Posted by Jim/TX/GA

There is a bracket sold that puts the big master switch down by the starter motor using one starter mounting bolt. When installed there, it is easy to connect the master switch into the cable that runs from the starter switch back to the battery. Everything is close to that location.

http://www.mikes-afordable.com/product/M14300DK.html

[Tom Wesenberg]

Originally Posted by bbrocksr

Really? Most cars aren't finished because of wiring disagreements?

Bill

Reading these threads instead of working on the car is what keeps them off the road.

[BILL WILLIAMSON]

Is EVERYBODY switched now?
Anybody got thet pic of a Guy beatin' a DEAD HORSE?
Bill Bored

[Dave in MN]

Originally Posted by Tom Wesenberg

Reading these threads instead of working on the car is what keeps them off the road.

Hey Tom,

You provided the best chuckle of the day for me. Thanks!
Good Day!

ps: It has been one of those days!